What are some good DSLRs that I can buy for a really good price?

Right now, I'm thinking about buying a Canon Rebel t2i for 200(a steal), or a Canon Rebel t3i for 479. I was wondering if somebody could make any other recommendations. I'm only looking to spend 500, maybe 600. Also, I need this by mid-August. If, you're in the New York City area and you would like to me your DSLR for a good price that works to.Thank you!

Also, is buying a DSLR used a good idea? If not what should I look out for?