RE: how much?
I found an inexpensive combo. I purchased a Five-Jet for $350 and put a kit-built Wren MW54 I purchased for around $1,500 on it. The plane looks like an 80% Boomerang which is ideal for a 54 size turbine, Wren, Ram 500, PST, etc. Should be very docile. Check Wren's web site for a picture of the Wrenegade which is an updated version of the Five-Jet.
I have also put a Wren MW44 on one of the pusher Bobcats with no retracts. I paid $150 for the plane and $1950 for the 44. The 44 fits with no modifications to the plane. The speed with no retracts is around 100-120 mph. Some people have put a bigger engine on it but it is really going to make the wing loading go way up. The little 44 is perfect.
Hal