This is my perception of Best Offers with relation to this topic.
There is no advantage at all to a seller submitting a best offer to himself using another ID, unless - and this is an incredibly wacky possibility - unless he didn't want to sell an item after he'd listed it, and preferred not to actually cancel the listing for some reason, and had a reason for not using the BIN button with his other ID.
In other words, it's a convoluted scenario with no discernible advantage or purpose.
1. If the seller wanted to create an impression that his items are moving (let's assume the seller has multiples of the same items up for sale, all the time, and he DOES want to create an impression of movement to entice watchers), there's no need to make himself an offer; he could hit the Buy It Now button rather than make himself an offer - but even so, I'm not sure that a real sense of movement is created. (See below *)
2. If the seller wanted to create an impression that lots of people are making bids on his items and that an interested watcher should rush in now, that doesn't hold water since the offers are visible to the
seller, not the buyers. (Just checking - am I correct on this?)
It should be remembered that Best Offer is applicable ONLY to BIN items, not auction listings.3. If the seller wants his final value fee credited, he can indeed make an offer on his items with another ID, then accept the offer with his selling ID, then offer a mutual cancellation to his other ID, accept the mutual cancellation with his other ID, and get his final value fees. But he won't be reimbursed for his listing fees, even if he relists - if he is offering a fixed price BIN item. If the seller were continually making offers on his own items and then going through an Unpaid Item Dispute, he'd end up with significant losses due to continually having to pay listing fees without sales. There would be no point to this.
It should be understood that there is NO REIMBURSEMENT or CREDIT of the
Listing Fees - except in the case of items in the Auction format. The link to the appropriate eBay page is
here. The item must either be
unsold or the seller must have gone through the
Unpaid Item Dispute in order to qualify to get a free relisting.
* Now imagine that the scenario of the seller wanting to create the impression of his items moving is correct. Well, I can see that the auction format is ideal for this purpose. You can certainly create a sense of movement by shill-bidding on your own items. But as far as the BIN items are concerned... is there an advantage? How many buyers check on the completed sales of a seller? Not many. It's not instantly visible by doing a search for an item - it requires spending more time digging. It's something that I can't actually imagine would pay off - because the VISIBILITY of the ITEMS MOVING is not in-your-face as far as the buyer is concerned.
Shill-bidding on auction listings is real.
But I am dubious about whether sellers do, on a large scale, hit BIN on their own items, and I'm highly sceptical that sellers would give themselves Best Offers.
The only suggestion made so far which at least gives some interesting perspective on a possible reason for BINning one's own items is this Best Match malarkey.
That's worth checking in terms of seeing how sales affect positioning in Best Match. A seller MIGHT, I suppose, consider the lost fees and time spent with other IDs worth it, if his items hit the front page and crowd out the competition.