I'd like a new sports car for under $9000 but I can't find any online either.
Seriously, you're going to have a hard time finding anything new below $799.
If you're willing to shop refurbished, there are several at J&R
As far as new goes, Fry's has an HP/Compaq they advertise a lot at $799 (EDIT: flybywire beat me to it) which you can also get directly from the company in either HP
versions, and PCClub has this one
As long as you understand you're getting a very compromised machine at such a low price point.