Unless you really enjoy going to garage sales and thrift stores all the time, you might want to consider the time and gas money you're spending while looking for a $100 "good deal" on an entry level bike for a 12 year old. I'd recommend the small, mom & pop bike shops in your area. Support them, not Exxon. You won't have to fix anything. The shop owner will probably try to make you happy to get the return business as your son progresses through bikes as he grows. Look for the very local "good deal" on CL or in your local newspapers but don't drive very far to get it. When you eventually find one, you're son will probably be ready for the upgrade. Then, buy all the parts for it from the local bike shop guy. Don't pay shipping and throw away a new box to save $1.00 on a brake cable. No offense meant, just my recommendations.