This is one of the topics that comes up fairly frequently on the old question board on eBay... so I thought I might start a thread / post a some information about the how tos of Second Chance Offers.
EBay states that if a second chance offer comes into your eBay message box, it can be considered a legitimate offer, I think you should still think carefully about the offer.
Is it an item that a seller is likely to have more than one of? For example, I sell Tupperware, so I often will have several of the same item.
However, there are some things that should always raise suspicion. For example, I bid on, and lost, and auction for a 2nd hand child's top. I received an offer from the seller within minutes, stating that they had another just like it. I suspect that they were shill bidding, unfortunately this happened early in my association with eBay, I wasn't aware of how to check this.
Would others care to add their knowledge to this?