I think at one point in time, 9 ring ones went for about £1,200 - but that was a bit of a flash in the pan.
Is there not a story somewhere about some of them being made at King's Lynne? It's possible, I believe, to tell the two (KL or WW) apart by how the base is constructed?
Sorry, I'm dredging through the bottom of the dustbin of my brain for this - my comments might be a bit contaminated by coffee grounds and fag ash.
However, this sounds like a bargain to me if you like them.