I've lived in Toronto and now live 10min outside of the city.
I'm not sure of cheap hotel as I've never needed one but I always pass by this hostel which is in a great location.
In terms of Saturday night if you're looking for a club it will cost you about $20 cover to get in pretty much anywhere. I the like club This is London but you have to call the place and put your name on guest list to get in (a lot of nights its EXTREMELY packed I recommend getting there by 11:15).
If you're looking for a college bar a very popular choice is the Madison (no cover) or Brunswick House (cover is cheap $10 I think). They're both University of Toronto bars and FULL of hot college age chicks. Drinks are on the cheaper side for a place on Saturday night.
If you give me an idea of what sort of scene you're into and what type of food you like it would be easier for me to give you a recommendation.