I found myself in an interesting related situation, with the outcome potentially not very humorous.
I was top bidder on a "broken" Pioneer style calculator. My maximum bid was WELL above what the proxy system had arrived at, and I felt I was in the driver's seat. Then, I get an email via eBay from someone asking, "Is it possible to fix these calculators?" I explained that yes it was, and that the MoHPC had all the information he would need.
I also added that I was currently the high bidder, and that if he chose to bid, by all means jump in with both feet. I didn't want to be in the position of having enabled a competitor to justify a bid on the item, and then having that competitor bid it up to within a dollar or two of my maximum before backing out.
Well, he must have thought it over, but two days later, this guy is suddenly the top bidder. A review of the bid history showed he'd issued something like ten bids to get there. (After the auction closed, I could see that he had bid in $5.00 increments until he came out on top.)
As it turned out, a third party sniped the article from both of us, but I wondered: if my maximum been $20.00 higher, might this second bidder have backed out and cost me $50.00 for having given him some information? That would NOT have been humorous!