1) Johnny Mains is running an auction with (so far) 23 items of horror fiction interest, including books by Robert Aickman, R. Chetwynd-Hayes, Gary McMahon, Paul Finch, Joel Lane, Ramsey Campbell, Robert Shearman, Mark Samuels, Quentin S. Crisp, and Mark Morris. Many items are signed, limited, or otherwise rare and special. Go here to learn how to bid.
2) The auctions at Genre for Japan aren't live for another week, but I understand they've gathered some very nice items, so when the time comes you might want to take a look.
And, of course, if you have items you want to donate to either auction, you can contact them directly.