i think the auction went according to plan on behalf of the seller but not for the buyer. its a very simple ebay trick that some sellers use.
the seller lists the item for a buy it now or best offer but lists the item for way too much at a very unrealistic price. hopefully someone will see the auction and place what they think will be a very unreasonable offer for maybe half price or even less. they wont expect the seller to accept they simply submit the offer as more of an insult to the seller rather than a good sound offer...
if an item is worth ?50 then you could list it for ?300 or best offer. someone would see this and make an offer for ?100 hoping you would see this as an insult rather than a serious offer. you could then accept the ?100 offer and get over the odds for your item leaving the bidder out of pocket.