If so, did you check "Messages" on "MY EBAY?"

If you have a second chance offer on MY EBAY messages, then the seller has more than one of the chip he's offered and is offering it to you as the underbidder at your bid. There is nothing "unethical" about that at all.

If there is no Second Chance offer in My Ebay messages, then you have been subjected to a phishing email that does not deserve a response. Instead; forward the email to spoof@ebay.com