Plenty of places to visit in Las Vegas, Nevada on the cheap.

1. Go midweek or off peak
2. Monitor sales on or search on Kayak, etc. Then book on hotel site. They have deals that include buffets, etc.
3. Plan the day around free shows - Bellagio Fountains, Volcano, Pirates - I forgot where they all are now
4. Walk around New York, Venice, Paris
5. Get a centrally located hotel - walk everywhere

Final tip - buy a case of small mineral water bottles at Rite aid for 10 cents each. Chill them in the room and take a few out. Otherwise you will be paying 20x as much.