WTB - Tri/Road bike

I don't think you'll find any tri bikes in that range.  I'd recommend a road bike...which you could always purchase clip-on aero bars for, if you wanted.  If you are new, I'd suggest getting a road bike anyway, and simply riding it as a road bike and not in the aero position.  You'll want to build up a lot of endurance before you worry about aero position, etc.  Also, if you go on rides with other people, they don't want anybody, much less a new person, riding aero in group rides. 

Check out eBay for good deals, but I always support my Local Bike Shop.  I do know that Felt brought out a entry level road bike with the Garmin-Chipotle paint scheme and that was around $800 new...but that is about as low as you go for new bikes with decent components.

Also, if you are new, and you don't know much about bike componentry, you probably still want to visit your local bike shop and find out the differences...especially with levers...there is a lot of variance from the low end to the high end.