Non paying bidders I find depends on what country the bidder is from, I found that bidders from specific countries are much, much more likely to back out from following through with payment.
At one point I was getting so many from one specific country I just had to close my auctions to that country which I really didn't want to do.
Bidders from USA and UK I found very, very rarely didn't follow through with payment, it happened around 1 in 500-1000 transactions.
But yes Green's auctions are very suspicious and also why didn't he offer second chance offers to the next highest bidders in the original auction? that is normally what happens in the rare occurrence the highest bidder backs out.