Going once, going twice...

Knickknacks fill the tables. Stacks of books sit on shelves. In a matter of hours, all of it is sold on the auction block to the highest bidder.

Every Wednesday there’s different stuff, and each item has a story. And every week the auction draws a big crowd.

The warehouse itself is rather plain: cinderblock walls, painted green floor, dusty ceiling fans. But here, professional antique dealers and eBay sellers sit alongside collectors and hobbyists. Some people are there to find good bargains, others simply to enjoy the thrill of the hunt. A few are there out of curiosity. In the back of the hall is a snack bar called The Gavel Galley, where they sell American chop suey and slices of homemade apple cobbler for $2.50.

Live auctions like this one are held every day across the United States, and a quarter-trillion dollars worth of stuff is sold on auction blocks every year, according to the National Auctioneers Association, which has designated this Saturday as National Auctioneers Day.

Life in an auction house like Kelley’s is something like “Antiques Roadshow’’ meets “The Price Is Right’’ meets “Dallas.’’ There’s history; there’s competition. And there’s drama.

“It’s a three-ring circus,’’ said Margaret “Marg-e’’ Kelley, who runs the auction house with her brother. “You never know what’s going to happen each week.’’

There are the regulars, the familiar faces. There are the owners — founder and CEO James “Jimmy’’ Kelley, who was in a car accident that left him paraplegic and attends auctions in a wheelchair, and his flamboyant sister, Marg-e, who used to work in theater and once managed the Charles Playhouse in Boston. There’s Michael Lynch, a professional numismatist who could dump a jar of pennies on the table and spot one that could be auctioned off for $500.

The auctions bring in standing-room-only crowds. Admission is free; the auction house makes money by taking a 15 percent cut of each item sold.

“It’s a strange industry,’’ said Marg-e Kelley. “I did it because my brother needed help doing this. This is the richest character study ever. It’s just strange. All day, every day, I’m just amazed.’’

Before each auction, photos of the items are posted online (www.kelleyauctions.net). The merchandise can be inspected in person between 4 and 6 p.m. on the day of the auction. Prospective bidders circle the merchandise. This is where a poker face comes in handy; you don’t really want others to know what item you plan to bid on.

As an appraiser, Kelley has done her share of dumpster-diving and says she even has to “play shrink sometimes’’ with people who consign their stuff for auction.

She runs the show with a stage director’s flair. Green-and-purple rimmed reading glasses sit atop her long silvery white hair. A cellphone is usually to her ear, and in one hand she carries a piece of paper that lists people who plan to bid by phone, some from as far away as South Africa and Denmark.

“Five minutes to curtain time,’’ she says at 5:55 p.m., as she strides through the crowd.

She tells everyone to quiet down: “If you need to have a conversation, use your inside voice, or take it outside.’’ The clock strikes 6 p.m., and the auction begins.

A row of men stand in the back, their arms folded across their chests. One man with a thick white beard rolls a lollipop back and forth in his mouth like a toothpick. Another wearing a Patriots jacket, with a ballpoint pen tucked behind his ear, settles into a seat.

All eyes are on the auctioneer, Guy Trudel Jr. He stands on a platform at the front of the room, known as the auction block, like a DJ behind decks. A priest at an altar.

Trudel’s dark hair is slicked back into a ponytail. He sports an Abraham Lincoln-like goatee and wears a plain black short-sleeved polo shirt. His stocky build and muscular arms make him look more like a football player or nightclub bouncer than a professional auctioneer.

But Trudel, 30, has had his auctioneer license for eight years now, and owns Trudel’s Auction Gallery in Bellingham with his father. He’s been calling auctions for Kelley for three years.

He calls out bids at a rhythmic, rapid-fire pace with a mouth that would make a beatboxer jealous. His rat-a-tat pitter-patter spit-fire voice never skips a beat. Whenever a bid is made, he subtly points to the person who makes the bid. The bids come fast. Both of his hands are moving. Words fly from his lips at warp speed, until he ends the sale with, “Going once . . . going twice . . . sold!’’

When a bidding war unfolds, an air of intense concentration fills the room. But only briefly — followed by a sigh of relief. Tension is released once the item is won.

Trudel’s eyes scan the room constantly, like a quarterback surveying a football field. Bidding signals happen fast: A hand darts up for a second. Someone flashes a piece of paper. It’s like spotting a streak of lightning: Blink, and you could miss one.

“You have to learn how to be quick,’’ said Trudel in an interview later. After all, there’s a lot of inventory to move: Hundreds of items must be sold in a matter of three to four hours.

Trudel encourages everyone to use bidder cards. “You scan for that white flash before your eyes,’’ he said. “After you learn who your clientele is, you learn who to look at for bids. You know certain buyers are there for high-end porcelain. Certain buyers are there for silver and gold.’’

Similar scenes play out elsewhere around the state. There are 812 licensed auctioneers in Massachusetts, and several of them conduct antique and collectible auctions south of Boston. There’s Broadcove Auctions, a busy, family-owned auction hall in Hingham that sells 300 to 500 lots per week. Couite Landry Auctions hosts small country auctions at the VFW Hall in Bridgewater. There’s also Abdou Auctions in Dedham, and Flanagan’s Auction Gallery in Brockton.

Every auction hall has its share of drama. And the auctioneer sees it all.

“Sometimes you do see funny stuff,’’ Trudel said. “When people are joking around in the back, not thinking that anybody can see them. Sometimes they don’t like each other at auction and they bid against each other, just because they despise each other.’’

On this recent Wednesday night at Kelley’s, a highly collectible Lladro porcelain figurine, about 16 inches tall, of a young woman in a dress holding flowers called “Allegory of Youth’’ goes up on the block. Pat Fredericksen, a retired school nurse from Randolph, wins with a bid of $220.

Fredericksen and her husband, Jim, have been attending auctions since they retired 11 years ago. They were there for the first Kelley auction and watched it grow to where it’s hard to get a seat now.

“It’s standing room only. Get here at 5:30 p.m. and it’s hard to find a parking space,’’ said Jim Fredericksen, who was a teacher.

Lionel toy trains go up. The high bidder is Gregory Myers, of West Bridgewater. He estimates the model train cars date back to the 1950s. His winning bid: $225.

A “lot’’ — or grouping of items — of New York Yankees memorabilia goes on the block. Everyone boos.

“I think it’s a fun business,’’ said James Kelley, a familiar figure. A Weymouth resident, he’s a proud alum of Cardinal Spellman High School and Massasoit Community College, and got his bachelor’s degree from Bridgewater State. A few days after he received his auctioneer license in August 1999, he was injured in a car crash that left him paralyzed from the chest down. After several years of grueling rehab, he finally got to open his auction house in November 2004.

He says he’s glad he’s not competing with big-box stores that sell mass-produced goods. At auctions such as his, there are “so many things you can buy for your home or office that you can’t buy in a store or a mall,’’ he said. “Like a 75-year-old mahogany desk that’s stunning, with craftsmanship you don’t find anymore. It might be dinged up, but you can get it refinished.’’

“It’s modern-day treasure hunting,’’ he said.

A few years ago, he said, someone brought in a circa-1904 Stickley desk, and it sold for $214,500. In February, an autograph book containing signatures of Babe Ruth and the 1934-35 Boston Braves sold for $7,000.

And just last month, someone brought in an old painting with holes in it. After some sleuthing, Kelley discovered that it was quite valuable: It was an 1881 oil-on-canvas maritime scene by William Formby Halsall, and it sold for $7,250.

The owner thought it was worthless. “He was thrilled,’’ said Kelley. “We thought we’d have to call 911.’’

Emily Sweeney can be reached at esweeney@globe.com. Follow her on Twitter @emilysweeney.