I'm looking to use it for exercises and to ride with my kids for fun. I figure I'll ride it 15 miles on average workouts. I keep hearing that if I buy a bike at Target or Walmart is will just fall apart on me and that I should buy the bike from a bike store. I also heard that I need to spend at least a few hundred if I want a good bike that's gonna last me though what am I looking for exactly? How do I know if a bike is good?