As a poor 20 something year old in Vegas living as a local, for a few years, I used to just go to the free buffet nights at certain clubs to get food because I couldn't afford anything except maybe a cheeseburger from McDonalds or a bag of tacos from Del Taco. I will say, certain clubs had some mighty delicious buffets and others not so much. Also usually since you're a local, the girls would just sit and chat/eat with you which made for some funny and interesting conversations.
Don't knock the buffets until you try them, some fine fried chicken and potato salad at these places