Grey Flannel Auctions, SCP Auctions, Pristine Auctions are a few I use for Spurs stuff. Grey Flannel doesn't take card or paypal and you have to pay by check or money order so haven't bought from them yet. Meigray is good but pretty expensive. I also have used Beckett Auctions who were great in posting directly to Australia.
Is Pristine auction legit? Long time ago i got a David West signed jersey that was from Pristine auctions and came with a LOA from them but kinda half half on its authenticity. I was going to sell it but because im not 100% about it, i just cant.