Several hundred dollars a day

A good time in Las Vegas isn't cheap. 

If you exclude airfare and hotel, the areas where you'll spend most of your dollars are food, entertainment, and gambling. Exactly how much money you will need for your Vegas vacation depends on your lifestyle and spending habits. You can spend as little as $50 a day but you probably will have to sleep in a hostel shared by many people, eat one meal a day, walk everywhere, not gamble, avoid the shows, and just watch people go by and feel miserable- $50 a day in Vegas will not get you far.