Turns out they'd gotten another email address of mine, probably scraped from the net, and their spam was flowing in from a new hole. I decided to submit a 'remove request' and see if they were any better behaved these days, but that just doubled the sewage.
So I've closed the new opening. Of course I'll never purchase anything through Buy.com. I'm disappointed that Google Checkout hasn't dropped them.
Conde Nast is the king of the named (public) spammers, but Buy.com is a close second!
I hope they're not long from this world. Please avoid them.