Got them from e-bay. One was new (put in a best offer of $250, was $285 shipped to my door) the other was not new (was $278 shipped to my door). they both needed warmers but that was it. All purge, fuel safety shut off, and switches were included. But... i probably have about $1000-$1200 in my origanl kit. Thats including N20 and fuel filter, auto warmer, fuel saftey switch, window switch, extra N20 solenoid etc. Actually my first kit i bought for $300 off e-bay. But when i added all the safety things it started to add up quick. Had twin bottles with it also. So thats 3 kits i got for under $300.
i know 200hp seems high, but i think i am doing it as right as possible. i have been running a 170 shot for a while now so 200 is not that far a stretch.
And like Hemiram11 said, wbw1 is shooting way more then me. im not saying that my motor will last forever, but if you do things right and dont cut corners, you can run N20 safely for a long time.