I think I'd agree with kf5nd that for really young kids an Xmart bike is fine. Before they use it make sure you (or your LBS if you're not comfortable wrenching) go over it to make sure everything is assembled correctly, tightened up correctly and in good order. My son has had a few Xmart bikes and all of them had parts installed wrong or poorly. As they get older Craigslist is a good bet for upgrades. We picked up an old 20-inch Schwinn 6-speed when my son had outgrown the X-mart bike. It has done 300+ miles on family rides, riding to school and mini-tours with no problems -- not bad for $50! I would say somewhere between 8 and 10 kids are ready for a real quality bike like you find at the LBS. At that point all the things the guy at the LBS said are true and actually meaningful to you. Good luck with your search.