The reality is that alot of people bid things up, and when it comes to paying, they either dont pay cause they changed their mind and realise they got caught in a bidding war, or meaningly dont go ahead, so the seller gets frustrated and their mate (who was 2nd in line with a much smaller bid) trys to nick it via a email.
I have a few mates who sell pins on ebay, and when it comes to the buyer paying up, they contact the buyers to find over and over again,that the buyer has dis-appeared into the wood work, at least half the time.
But a email soon comes from another bidder offering cash offsite, at a much reduced price.
Some sellers think, a cash price today, is better than a rubber cheque/ebay bid of tomorrow. But yes, it sucks to have listings pulled all the time. 
The big problem with that, is it's creating a false market. Machines ending at high prices, buyer not paying up, machine gets sold for a lot less outside of eBay. The people watching the original auction are led to believe the game sold at the auction end price.
Not good.
