Just look on ebay. I scored a Presonus Firebox for $108 used! (I got super lucky) SM57s are all over the place. At most, $100 new, but they pop up everywhere from craigslist to ebay. If you went all used, you could probably get an interface and a SM57 from 200-250 bucks.
Reaper isn't exactly free either. There is a free full-functioning demo of it that never expires, so on that hand it is free. They don't believe in crippling their software, so you can use the demo forever with full function. I used it for 97 something hours before I just bought the license for like $50 bucks or something.
EDIT: Thanks for the links Nolly, I'll check them out tomorrow. Going to the Rockies season opener right now though! GO ROX!