The 'second chance' offer is not uncommon but watch for some 'red
flags'.  If the seller contacted you very soon (same or next day) after
the end of the auction there is a good chance that you were bidding
against a shill, bidding to drive the price up.  Check the feedback on
the 'winning' bidder.  If he was a legitimate bidder but backed out you
should see negative feedback from the seller.  I have sold a number of
items on eBay, and when I've had a winner refuse to complete the deal it
has usually taken several days to get to the point that I can ask eBay
to credit my account for the listing fees.  And if a sale falls through
the seller can re-list at no charge.  Also, if the seller contacts the
'second place winner' and completes the deal there is none of the eBay
protection for either the buyer or seller. BTW, if you think that there
was shill bidding going on, report it to eBay, they want to know.  They
can easily check to history of both buyer and seller and if they see a
pattern they will act.