Hmm, I got a huge deal on them (I have contacts in the RC industry). But, I can tell you what they should cost;
The motor (AXI 5345) $240
Controller $260
Throttle potentiometer $14
Battery $600 (I paid $435)
Charger $225
Misc. materials about $300 (chain, sprocket, pulleys, belts, bearings, aluminum, etc).
Machining equipment? Hmm, about $5,000!
Oh, I am looking at a used TIG welder tomorrow.
Matt