eBay Second Chance Offerings

I had bid on a GNS430 and lost. A day after, an email stating the winner did
not complete the transaction and I was being offered a "second chance
offering". The email looked good, had "eBay" sort of format, but was a
fraud; the buyer had completed the transaction.
A week later, I won a bid on a GNS430. A bidder email me saying he had
received a second chance offering.
This seems to be a continuing attempted fraud on high dollar items.
One needs to be very skeptical about what emails are taken seriously.
Wayne