Please don't forget that at the present time, and possibly for the foreseeable future, the R66 isn't EASA registered so you wont be able to get your PPL in one even if you buy it.
I have flown all of these machines and I would say from my experience if you want to have a quick comfortable ride from A to B with or without passengers a B206 is the best choice (STEER CLEAR OF ALL AGUSTA BELL 206's - they are a wallet melt down waiting to happen) but if you want the aircraft more for fun and the pleasure of flying get an MD500E.