My friend and VCCC member, Bill Kirby, just had this happen to him. He bought an Avalir from a member of the Vacuum Collectors Club on facebook (Rob Walton's group). Sent the money by walmart to walmart transfer. The money was picked up, and of course, no vacuum ever. The seller tried to say he was in an accident and his mother would ship, etc. All kinds of excuses. To make matters worse, the seller is still on the facebook group, scamming other members.
The police don't want to get involved unless the fraud is over a certain amount. Bill's only recourse is to sue. Luckily, as a former Chrysler employee, Bill is entitled to free legal service with corporate lawyers.
A bail bondsman (and fellow vac collector) helped Bill obtain the seller's current information (current address, previous address, previous convictions for fraud, etc.). Will be interesting to see how it all plays out.
I always say, NEVER send money other than through paypal, to anyone you don't know, for any vacuum or part. Be especially careful of members of facebook groups that you don't personally know.