Paul...

I think that if the SELLER initiates the offer that it's unethical to piggyback on the thread with a lower sale price for the same item.

If the thread is initiated by a BUYER's request for a chip, however, the proceedings could wind up being a reverse auction... which I think is a great concept. I think it is very ethical to undercut a previous SELLER poster's offer if the request for an item had been initiated by the buyer.

Now, go to sleep!