I want to buy a bike, but I don't know what I'm looking for. I know some of you have bikes, so can you give me your reccomendations? I obviously need something that's built for a heavier frame, but I don't want to go to a bike store and say "Hey, I'm fat, give me a bike whose tires I wont' flatten in 3 uses". Also, what should I expect to pay? I figure with gas currently at $4.09 in my town, buying a bike would pay for itself pretty quickly... Help!