You can buy a pretty nice bike for that price loaded with goodies, (motor/susp) depending on your area.
You can build a pretty decent one from the ground up for that price as well, but you will have too keep an eye out on here, local, Craigslist, eBay and pounce with cash in hand on the good shit around. Good shit is all around, just keep both eyes open and the wallet hot too.
Location?