I always appreciate it when someone gives me a lead on comic books but, unfortunately, I steer clear of Paramount Book Exchange because of the following experience.
In the 90s they held occasional sales where huge stacks of comic books would be put out at the front of the shop, all priced 25p. Most of it was drek / mid grade, but you could find the odd BA book, stuff like Astonishing Tales, Fear - Deathlok, Morbius appearances.
I went in very early one morning when a sale was on, the shop was empty, and the younger of the two brothers was there 'managing'. I knew I'd been identified on previous visits as a collector, and I recall him rushing up to me predatorily, in a bit of a frenzy, demanding...
'Although these are all marked 25p, I'm charging you 50 each!'
Thought it was a bit infantile and desperate, felt quite sorry for him and I just replied..
'Well, that was suicidal, wasn't it?'
Turned my back and walked out. Yes, seventeen years ago, never been there since.