Bluebook on the Jewel preamp 1985 is $250 retail; about half that wholesale...Don't know if that corresponds to your prepre. From the description it sounds like it should be in the $100 - $150 ballpark.
Win Laboratories Phono Preamp Value???
I have the opportunity to purchase a phono preamp made by Win Laboratories (Dr. Sao Win). It's designed for a MC cartridge, and has LOTS of gain! It is powered by a "wall-wart" looking AC transformer, but with three wires going to it, so different than the typical wall-wart. I don't know what such an item would be valued at. Anybody know? Thanks.