Not off eBay... but my BIL attorney had an estate to sell that included 2 long boxes of comics. He had an offer of $700... asked me if I'd pay more... sight unseen I said, sure, and paid $800. He thought it was mostly monster mags.
Included were the following complete runs: ASM 15-67, FF 31-80 with 2 FF49's, XMen 9-50, JIM/Thor 113-150, and other assorted Marvels.
Plus a ton of other Gold Key stuff: runs from Tarzan, Twilight Zone, a complete run of Magnus Robot Fighter 4000AD, which I'd never heard of, but which is apparently quite popular.
And.... the monster mags did a lot better than I thought. Nice haul.