Not too long ago (maybe a year or two ago), there 
was this really good article about a scam artist 
on Ebay. I think he was a collectible figurine 
seller. He was very established and trusted in 
the figuring-collecting community. But then he 
decided to disappear--- so he sold his usual 
figurines. He received money from the top 
bidders, but also wrote to second and even third-
highest bidders that the top bidder had backed 
out, and they could have the item for $x. Many of 
them were happy to jump at the second chance. He 
ended up getting paid two or three times for each 
item, and never delivered a single one, and just 
disappeared. No one was suspicious until the 
collectors started talking on a collector board...

That's not to say that this seller is preparing 
to run off to Mexico. ^_~ But it is to illustrate 
the point that it can be a potentially hazardous 
situation, where someone may double-sell the same 
item and trick one or both of you. The idea that 
the high bidder was perhaps a shill was also a 
good thought. You might try emailing them 
personally and asking them about the 
circumstances. Most people will be happy to 
respond.

Also be careful if you don't get the 
official "second chance" Ebay email. I've 
received it a few times for buying non-cel items, 
but I've never followed up on it. Still, it gives 
you the right to leave feedback.

Whatever you choose, be sure to protect yourself 
if the situation doesn't feel right. ^_^