I bought a bike from someone\ business like this when stationed in RAFG (Germany), you get notified of posting overseas, order what you want, tax etc free. Pick it up when you get overseas (or day before you go) - sold it 3 years later for what I paid for it....It was as "dodge" as this, though no web site and worked fine - I know loads of people who bought cars like this kept on the road for 6 mths in Germany, then sold on.....though that was soon stopped.
I would try to pay a small deposit and pay the remainder on collection (same as a main dealer), if you can....