Hey everyone. I'm a 22 year old college student in need of help. Over the past three years, I have gained approximately 100 pounds. Though I had a bike when I was younger, I'm much too large for it now. I was wondering if you all would be able to suggest a bike (New or used) that wouldn't exceed a $300 budget? Most of the riding I plan to do will be on paved roads throughout my city. I'm approximately 6'2, 377lbs. Any help you can provide would be helpful.

Based on my size, are any of these ads worth checking out?
http://richmond.craigslist.org/bik/2178841121.html
http://richmond.craigslist.org/bik/2143514840.html
http://richmond.craigslist.org/bik/2177840306.html
http://richmond.craigslist.org/bik/2150770067.html