Problem: This is a first for me. Received an offer on an item,

[wordlythings]

Problem:  This is a first for me. Received an offer on an item, but the bidder changed his mind and cancelled the offer so that he could make another lower offer. The high offer was on the top of my list of messages, so I responded, yes. However, the real offer was the lower price but when I sent an invoice it was for the high offer, and now I can't change it. I would have thought that eBay would not have let me accept the cancelled offer?  Do I have to cancel the sale and get the buyer to make a new offer? Of course, the buyer just joined eBay, and so is inexperienced!   What to do?  (Rereading this makes me realize how confusing it is....;)