Gambling depends. You can pay 1 cent on a fruit machine per spin if you want, and I still got free drinks. Though 25c and $1 is more normal. Blackjack is more expensive, you might find some $1 tables, but 5 and 10 a hand is common.
Drink is fairly expensive in the hotel/casino as you'd expect, but there are some dive bars and casino that offer 1 dollar beers.
Food depends what you want. Plenty of normal USA hard rock cafe type places to eat, plenty of high end placed too. I'd say 20 dollars a person up is about right on strip, but I'm sure there are plenty of cheaper places if you seek them out too.
So yes, how long is a piece of string

I guess Google is going to be more helpful.