I'm afraid I don't know much about this field. The few pulps I've actually bought (via ebay) were purely to get hold of specific stories I wanted to read that had not been reprinted in book form.
I don't collect pulps, sf digests, etc. However I've bought a few over the years without being concerned about condition. They sometimes relate to my interest in the Inklings. Thus, having read Donald Wandrei's "Colossus" as reprinted in a book, I was convinced that this was s story whose author and title C. S. Lewis couldn't remember, but which he acknowledged as a source for his short novel The Great Divorce. He could only have read it in the issue of Astounding in which it first appeared. (I was sure that Astounding was available in England at the time.) So I thought it would be interesting to own the issue and see what else CSL might have read in it. Arthur C. Clarke gave Lewis a copy of an sf digest with one of his stories in it. I thought it would be interesting to have a copy of this issue that Lewis read cover to cover or at least for the most part, since he wrote to ACC about it; so I got a copy.
