The Planet X exocet is about $1100 and steeper than their old bike.

There is also:
Felt B12
Cervelo P2
Specialized Transition Pro

Those three are all about $1800 give or take. All well designed aero frames, available from any dealer I would imagine.

Another place is RAcycles. They have a ton of frames in the $1000-1500 range. I won't quite say they are as aero as the above, but good quality new old stock frames:
http://www.racycles.com/sales-center/triathlon