I’ve got Fungi from Yuggoth!
(I know there’s a ointment available now to take care of that, but…)
Seriously. I found a copy of the 1971 Arkham House paperback in damn good condition. First edition. And a copy of The Survivor by HPL and August Derleth. At my local Goodwill. For a quarter each.
<Doing the happy bibliomaniac bragging dance…>