JL35:
almost all don’t, it’s a rare one that does...and often vintage gear actually sells for far far less than those hopeful asking prices...
+1.
The ultimate example of speakers increasing in value over time (actually just the drivers themselves) would undoubtedly be drivers made by Western Electric in the 1930s, originally for theatre applications but now revered by many audiophiles and worth not so small fortunes. Vintage Tannoy speakers and drivers have also increased greatly in value, as have a number of others including certain vintage Jensen models, Altec’s version of the Western Electric 755A driver (used in Acoustic Research’s original AR-1 speaker), etc.
I would draw a parallel to the field of antique radio collecting, which is another hobby of mine. Among vintage radios, say from the 1930s, 1940s, and 1950s, most are worth much less than a non-collector might envision. But a few that are special in some way (as well as being rare) are worth vastly more than might be expected by someone who is not particularly knowledgeable about such things.
Regards,
-- Al