You sister should be very careful about accepting offers made on an item being sold at auction. While there is no problem if no one places a bid before the offer is accepted and the listing closed, once a bid is placed the any offer made becomes void and the option to make an offer is deactivated. This has lead to some issues with both sellers and buyers not understanding how things work.
In many states if you are selling at auction and someone places a bid in good faith and you then accept an offer to buy the item outside of the established bidding process without first closing the auction and withdrawing the item from the sale, you could find that any bidders could have a legitimate complaint against you for not conducting the auction in good faith as required by the auction laws of those states. Thus the killing of any offers once a bid is placed. It avoids the seller from potential legal issues. Naturally, this can annoy both the one making the offer and the seller that wasn't quick enough in accepting the offer.
Frankly, I believe eBay decision to include this option in auction listings is ill advised. Although eBay, not actually being an auction business but merely a venue, wouldn't have any legal issues from it, the seller could. In fact, depending upon the particular state where the seller conducts business, they could list losing there license and/or other sanctions. I would advise your sister to check with her state's auction regulating authority to check with her state's auction laws regarding the matter.
"It is an intelligent man that is aware of his own ignorance."
