I too recall when the Avon one-shots took off, and how sad it was thinking I'd never get nice copies of all of them. Over the years, I found low grade copies of a few of the amazing sci-fi covers, but to this day, several elude me. I think the run is truly under-rated: think of the complete set of one-shots and all the great genres represented (beside super-heroes). It's a pretty stunning cross-section of horror, mystery, crime, western (think Chief Victorio's Apache Massacre!), adventure, romance - even a humor book or two IIRC.