As a seasoned ebayer...I've gone for "second chance" offers once or twice when my top bid was still way below the value of the item on the auction block.
Recently though...I've been getting second chance offers on items that have been listed for seven days and I put in a "max bid" early and then moments before the close of the auction, someone places a single bid that takes the prize. So...I lose and I'm sorta thankful that I didn't have to pay "my max" bid and I'm wondering why the other bidder felt it was worth the price.
A day or two later...I get a "second chance" offer that says the seller has a duplicate item or the "high" bidder now doesn't want to follow through with the purchase. I think this scenario is a "scam" and the seller and high bidder are in cahoots together.
With "second chance offers" now...I usually email the one who offers it, that my policy is to never accept such offers as I believe this system of making a sale on ebay is one of only a few flaws in the ebay system of Internet bidding and sales...highly open for fraud of all kinds.
Of course...never having ever sold a thing on ebay...maybe "all" second chance offers are "on the level" but they sure seem like something fishy is going on when I get them.
Like mentioned above by Fshklr...
"Always be alert...it's the Internet...right?"

.................on this blistering Summer day!