the mayhem pro is 550 for the engine, pipe, and kit.

you can look on ebay for it cheaper. i'm sure you can find a brand new one on ebay for 500 dollars or less. with the .21 engine, and pipe. but you could always buy the mayhem pro w/ out the engine, and stick a O.S. Rg engine, with choice of pipe.

the mayhem pro w/out engine is 350 on horizonhobby.com, and can be found cheaper on ebay, i think