Buy cheap, buy twice. Sounds like you need a hybrid to me. Unless you intend a lot of curb hopping, suspension bikes aren't really needed for "dirt" trails. And those knobby tires get real real old real fast on pavement. Wal-mart employees don't know how to setup bikes and they won't service it a month later when the cables have stretched. If you spend "$700" the first time you'll enjoy the bike for years to come, have less maintenance issues and have a better bike to re-sell in t.he future