I'm not sure if I'm the resident law professor you referred to, Jim, but here is my inadequate response. Absent a statutory prohibition to the practice of contacting buyers before the auction is over and offering the chip for a lesser price than the current bid, I think the legal matter is simply one of contract. By getting access to eBay, one enters into a form of contract and has to abide by the terms or that would be a breach and constitute grounds to rescind the contract [delete the person's password]. But contracts are not like roses which I gather are always roses. Contracts depend on the terms and while I am not conversant with eBay terms [I find them confusing as do others], they may be inconsistent, incomplete or unenforcible for another reason.

Having said that [and not accomplishing very much, I know] to me it comes down to ethics. I look down on people who would undercut eBay sellers and the auction service itself. However, if I am bidding on a desired chip; get an unsolicited offer for the chip at a lower price, I certainly wouldn't continue to bid up the price. I am troubled by what I would do next. I don't think I would buy from the offeror. But I'm human. On the other end of the spectrum, when I find a chip listed for sale that is common but is being offered for a high price, I regularly contact the seller and give him whatever information I have on the chip--it's up to the seller whether to act on it and whether to post the information. I have contacted a number of sellers and most have thanked me and reported the information. I would not, however, contact the listed buyers unless I had proof that a fraud was being committed or about to be committed. If I thought that, I would notify buyers and eBay but only after giving the seller a chance to withdraw the fake chip and correct the fraud. I add that I have not had such an experience to date, however, except where a dealer was offering a chip alledgedly from a Los Vegas casino that never existed, and he withdrew the chip.

This is too long a post though I have other thoughts.