A few thoughts from my experience (I live in Toronto):

- fixed-gear bikes on craigslist in Toronto are over priced
- most local bike shops in Toronto are also over priced especially for fixed-gear related stuff (e.g. Urbane)
- don't be afraid to order from online retailers in the U.S.; the deals you can there find far outweigh the shipping, taxes and possible duty
- take your time; Toronto is about to be finally hit with some winter weather so you won't be riding tomorrow anyways

Based on your budget and desire for a complete bike, I'd suggest a wabi lightning.