Well, for dragging knees and wheelies and general fun, it will be ok. Like the other guys said, parts will fall off and general quality is poor. If what you're looking for is just a knock around fun minibike, it will be ok. Don't know how long it will last under that kind of strain.
But, if you want a true pocketbike for racing, get a name brand. Then, the wheelies and knee dragging will be way more inspriring! Expect to pay about 1200-1500 for a basic air cooled model. They do hold up well, though, and acceleration and top speed are much better. The Blata Elite 13 is what I have, and I've never regretted spending the extra $$.