That one looks sketchy. I don't see any brand name, so it's probably chinese.
The tiwanese make decent ones, most people I've seen on Kymco People scooters seem happy.
It looks like most of their 50cc ones are in your price range. They're good for around town, and i think you can get the bastards doing 40+ with minimal mods.
I really wouldn't trust anything out of china unless you can find a review on it. It's hard to find mechanics that will work on any of them, and new parts can be damn near impossible.
The 2year warrenty looks nice, but I dono what it covers..