Downtown Boston has become a playground for the rich, dominated by luxury condo towers with multimillion-dollar units.

The median price for a luxury condo in neighborhoods like the Back Bay, South End and Beacon Hill hit $1.4 million during the first three months of the year.

That's a phenomenal 22.7 percent increase over 2012, according to LINK numbers cited in this Globe piece.

Well it's all part of a global phenomenon that threatens to turn the world's top cities into "gated citadels," British author Simon Kuper warns in the Financial Times.

Global cities are turning into vast gated communities where the one per cent reproduces itself. Elite members don't live there for their jobs. They work virtually anyway. Rather, global cities are where they network with each other, and put their kids through their country's best schools.

Housing starts are on the upswing across the country, with a fresh batch of good news due out Tuesday from the feds.

But here in Massachusetts, construction of new, single-family homes has fallen to anemic levels not seen in decades, with no signs of a major uptick in the horizon.

And given the onward march of home prices across the Boston area, that's hardly good news.That is unless you think supply and demand just don't matter when it comes to housing prices.

Heck, if you own a multimillion-dollar Back Bay mansion, what's another half a million or more for a pair of extra parking spaces?

Well actually $560,000 for a pair of weed fringed spaces behind 298 Commonwealth Ave.

Check out this Globe story about the auction for the parking spots, won by a buyer who owns a $5.8 million home on Commonwealth Avenue and wanted some extra spaces for when guests come over.

Sounds like a lot, especially given the fact you have the Boston Common Garage nearby. It may not win any award for aesthetics, but at $18 for three hours, it's a bargain!

A nurse at a Boston hospital, Brittany wants to buy a condo but can't find a decent unit worth putting money down on.

At this point, she's all but resigned herself to renting for another year.

"If you like a place, you had better have an offer on it or it will be off the market tomorrow," Brittany told me in a recent interview. "You don't have a second to think."

No, she's not looking in Cambridge, Davis Square or Arlington.

Instead, she's looking in Natick.

OK, we all know it's tough to find a condo in the hipster zones of Cambridge and Somerville.

But for condo buyers in the suburbs, it's not easy right now either.

OK, when Realtors start talking about the market reaching a "tipping point," it can only be bad news for buyers worried about soaring prices.

It means things are starting to get a little crazy.

As we head into summer, sales activity is soaring, with buyers spooked by rising rates and the prospect of more price hikes ahead.

Boston is now one of the most competitive home sales markets in the country, moving up to No. 5, Redfin reports this morning.

That's up from No. 7 in April and suggests this summer will be long, hot and busy for both buyers and sellers.

Greater Boston is more competitive now than Seattle and Washington, D.C., behind only San Francisco, Los Angeles, San Diego and Orange County.

So what does "competitive" mean?

A reader and prospective home buyer, Katherine is wondering whether the real estate market will slow down now that summer is here.

In particular, she's worried that all the good homes were snapped before Memorial Day and new listings may start to dwindle.

Here's Katherine:

I was wondering if you could post something about Memorial Day weekend listings. I have noticed that a ton of homes that were on the market for a while (well not very long in this market but longer than a week) are being listed as pending this week and I had heard that after Memorial Day Weekend the home listings dwindle. In an already low inventory year, I imagine people may be extra stressed about the lack of homes so they are scooping up what's left. I was wondering if there is any truth to this or is it just the rumors that I have been heard. I was just curious was general market trends are after Memorial Day weekend in terms of listings- do they typically drop?

Boston-area rents rose more than 5 percent in May, more than double the national pace.

It's enough to make Greater Boston the fifth least affordable rental market in the country, behind only the likes of New York, Miami, San Francisco and Los Angeles, Trulia reports.

In terms of the pace of rent increases, Boston is No. 2 in the country right now, second only to Miami, which saw a 6.4 percent hike in May compared to the same month the year before.

So exactly how unaffordable have our local rents become?

There's speculation galore now about how steadily rising interest rates could cool the housing market.

But before the chill sets in, sales could very well go into overdrive as buyers seek to lock in rock-bottom rates before they are gone.

Interest rates have just topped 4 percent. OK, that's still incredibly low, but up sharply from 3.4 percent at the beginning of May.

If you doubt the power of the herd mentality to drive sales and prices in the real estate market, just recall what happened back during the nutty spring of 2010 as the expiration of the home buyer tax credit loomed.

Buyers bid up prices on homes in a scramble to grab the seemingly free government money before the offer expired, often negating the value of the $8,000 credit.

Could we see some panic buying over the summer if rates keep pushing up?

Don't bet against it.

Oh my, how things have changed!

A couple years ago, sellers were ready to do just about anything to move their home, with some desperate enough to pitch in on closing costs or throw in a free Hawaiian vacation.

But with the Fed inflating the market again with its multitrillion-dollar monetary manipulations, selling is now the easy part. (Here's an interesting Forbes piece that looks at the new housing bubble that's taking shape.)

The problem is, once you've sold in this fast inflating market, you are suddenly out there with all the other chumps bidding against each other for a limited pool of decent homes.

Sure, you may be able to sell and even get a price you would not have thought possible a couple years ago, but will you truly be able to move up to a bigger home in the same town?

If you are struggling to come up with tens of thousands of dollars down in order to buy a house, you are not alone.

Down-payment requirements are easing across the country, but they are still hefty here in Massachusetts.

When it comes to down payments, our state has the fourth highest average. If you want to get into a home here in the Bay State, you will likely have fork over more than 18 percent up front, according to a new LendingTree survey.

Only New Jersey, at 20 percent down, and New York and California, at just over 19 percent, has higher average down payment requirements.

There has got to be some sick joke here - after all, these are also all the states with the highest real estate prices. And, for that matter, the lowest foreclosure rates. Yet not only does it cost more to buy a house in Massachusetts and other high-priced Northeast markets, but it costs more up front. Much more.

If you are selling a home in this tight market, get ready to be hit up with a personal appeal from a buyer, complete with photos of smiling children and adorable pets.

What to do? Well, actually, it's easy: Head directly to the circular file and don't look back. Guilt is for suckers.

With not a lot of homes to choose from, buyers are pulling out all the stops when they find something half decent. That means trying to personalize their bids and gain an edge.

But when it comes to buyers, the only thing you should care about is what they offer for your house and what's in their bank accounts, not how wonderful their families are or how much they will enjoy your home after you have moved on.

It's all about the money, and that's OK.

Behind every bubble is a panicky rush to buy a suddenly scarce and coveted product before prices go up again. Get yours now and get it fast before someone else grabs it.

It was true for tulips in 17th century Holland and of homes in 21st century America, circa 2005.

Are we now in for a repeat, barely a decade later?

It's too early to say, but a new Redfin survey points to some big and pretty rapid shifts in how buyers perceive the real estate market.

Faced with scarce listings and rising competition, growing number of buyers are staying in the hunt and opting to ante up in order to get what they want, the survey of 1,353 active home buyers finds.

As prices head skyward, sellers are finally getting off the fence.

New listings jumped 12.7 percent in April, with a total of 9,350 homes hitting the market in April, the Massachusetts Association of Realtors reports.

It was the biggest surge of inventory since April 2010, when sellers rushed to get their homes on the market amid the frenzy caused by the expiration of the first-time buyer tax credit.

Yet this all may be too little, too late.

Even with the increase in new listings, it is barely enough to keep up with current demand, with the homes hitting the market getting snapped up as quickly as they come on.

Despite April's jump in listings, the overall number of homes on the market is still down by more than a quarter compared to the spring of 2012, MAR reports.

Roughly 16 percent of homeowners across Greater Boston are still mired down in negative equity, Zillow reports.

To translate, they owe more on their home than it is worth in the current market.

But if you are out house hunting, this stat can be useful. After all, it can show you the towns where home values held up better when faced with the ultimate test, the epic, years-long real estate downturn we are just now pulling out of.

Not surprisingly, the toniest suburbs have relatively miniscule number of underwater homeowners, with towns like Winchester and Manchester and Concord and Lexington are all below 5 percent.

Yet there are a whole bunch of additional towns out there that are hardly brand names, so to speak, but where real estate values have held up amazingly well.

Towns like Burlington (6.3 percent) and Topsfield (7.5 percent), Reading (6.0 percent) and Wakefield (8.7 percent), have negative equity rates well below the average for Greater Boston.

The good news is the number of Greater Boston homeowners owing more than what their castles are worth has dropped below 16 percent.

The bad news? Another 18 percent of Boston-area homeowners may be out of  the red, but still don't have enough equity to sell and buy another house, Zillow finds in its first quarter report on negative equity.

That means just over a third of homeowners inside the 495 beltway are stuck in place, unable to sell, unless, of course, they want to rent instead of buy.

If immigration reform actually makes it through Congress, it could unleash a wave of home buying.

How much? More than $500 billion in new home sales, the National Association of Hispanic Real Estate Professionals estimates.

And that's not counting another $180 billion in home-related spending.

Ever wonder where your neighbors are headed on vacation? If you live in Greater Boston, it's a good bet they aren't headed very far.

Trulia today is releasing its list of the top vacation home destinations for each major metro market, as well as nationally, based on a tally of searches on the real estate portal.

Of the top ten most popular vacation home destinations for buyers from Greater Boston, nine are on Cape Cod.

In fact, the only break from the pattern is Wells, Maine. Sorry New Hampshire, Vermont and Rhode Island, you are out of luck.

Let's not get big heads here, though. Sure, we love the Cape, though I'd argue traffic and overdevelopment is close to wrecking the place. Just get off Route 6 in Hyannis and take a scenic drive down Route 28.

But the rest of America is not so enamored with our favorite vacation playground.

If you plan to cash in on your house to pay for retirement, you have lots of company.

Nearly half of Americans 50-70 found say they are relying on the sale of their homes in order to come up with money for their Golden Years, according to a survey by Ameriprise Financial.

And given the survey came out in February, before latest jump in home prices, that number is probably even higher now. (Here's a Times blog post on the survey.)

In fact, more people are counting on sailing into retirement with help from a big real estate payoff than ever before.

That number, now at 47 percent, represents a big increase from before the Great Recession, when 39 percent said home equity would help pay for their retirement.

OK, there is an obvious disconnect here given that housing prices remain far below their peak in many parts of the country.

Yet part of me wonders what all the fuss is about. After all, people have been using their homes to help pay for retirement and college education for decades now.

I guess I am just a boring, single-family home type of guy.

But I am shaking my head over a pair of $3 million-plus sales in Cambridge, one a condo in Harvard Square, the other an historic home just off Brattle Street.

The sales are detailed here in a press release sent out by Hammond Real Estate.

Both sold in the same price range, but the condo is less than half the size of the house. I guess I just don't get it. Why spend $3 million for a 2,600 square foot condo when you can get an entire Cambridge mansion for $3.5 million?

Of course, that is one humongous condo - the size of a substantial suburban home. And you won't have the headache of yard work and maintenance, though you will certainly pay dearly for it in the condo fee.

Yet, let's face it, the Harvard Square condo is hip, while the old home off Brattle Street, as graceful as it may be, is not.