Found the ideal item on fleabay at £17.49 buy it now or best offer. I made an offer of £15.
This morning I had a counter-offer of... £22.50. Wondering what was going on, I checked the listing again only to find that the seller had raised the buy it now price to £23.99.
Intrigued, I did a little digging and found that, like most of these Chinese importers, the seller had several accounts, all selling the same sort of things and on one of them I found the same battery for the original buy it now price.
I really don't understand the business models of some fleabay sellers.