Our AeroSport EDF is a nice entry into the world of ducted fans. It is very stable and easy to fly, yet will go pretty fast if you want it to. We're using the XF-Fan with a 5100 kv brushless motor, which is a very nice quality package. It flies on 3 cells from 1500 to 2100 mah.
Plane, fan, and motor are around $130.
Let me know if you have any questions.
Scott
www.ModelAero.com