I agree. I found a great clydes bike (aka Hardrock mtn bikes,laso Trek and a few others) on Craiglists list, and I see bigger bikes (I'm 6' 1") daily for under $200 (most are in the $100 range). These are ridable as is, but a $50-75 trip to the Local Bike Shop will make sure. So if all you have is $200, you can be riding very soon.
After that, all you really need is a $20 helmet and $2 flat tire kit for your favorite X Mart store.
Jerry