Have you also noticed that if you "watch" an item with an "or best offer", you can get an offer sent to you, unsolicited. I found this annoying....if I wanted to make an offer, I would have done so and if I had to get everything set up such that if the offer were accepted, I would have to pay - so be it. But to have offers generated and sent because I put a watch on an item is excessive. What's next, auto-offers because I viewed an item?
Also, this has happened repeatedly and in one case, the offer that was sent to me was significantly lower than the asking price. I let the offer expire and continued to watch and the item was claimed to be sold at the listed price. I don't bid on much at all, but I think I will always put in a lower offer at first.