Originally Posted by lugged
Upgrade all you want, then when you really get into it, get a good frame and transfer your upgraded parts over to the new frame.
If he does choose to upgrade, he's going to have to look for special parts, because the majority of parts are NOT compatible with those extremely low end bikes. If you choose to stay with that bike, do not upgrade anything, it's definately not worth it. A cheap fork, maybe a rockshox Judy, will still cost you the same price as the whole bike did. Or more. And I doubt that regular forks will even fit into that headtube, as most X-mart bikes don't use a steer tube, the use those 1 piece garbajo crappers.
Your safety is even compromized on very low end bikes. As most say "Not meant for offroad use" even though they are supposed to be 'mountain bikes'.