I was especially interested in this comment given the OP's choice of target market. Is the UK secondary market big enough... do you think you can take the business off the auction houses? My understanding of them is that a big part of their service, and why they might be able to justify larger fees, is the cellar valuation, all-in-one service e.g. for clearing out a dead relative's estate.

I definitely think there's something in the individual's secondary market and the competition that exists, e.g. B4W and also the online forums, prove this. It would also be nice to arrange selling of smaller quantities than cases. Just wasn't sure if that would reach the numbers in the OP's point.