Talk to the builder (I am assuming that is who is selling it). Let him have you look at EVERYTHING, logs, plane etc. Have him teach you to fly it, before you blast off in it. Fly it day VFR, (you would be anyway if you are teaching a primary student along the way). If you start to have a funny feeling after seeing the airplane, back down. I'm not a hell yes or a no way, but I'd do it in the right conditions.