91B

I have a 91B most likely produced around 1993. How much
is it worth these days ? The case was also purchased. Thank you

The Big Briar Series 91 theremins are a museum or collector’s piece which makes them priceless. Demand is low as you find very few playing the 91 series. I have seen Peter Pringle and Carolina Eyck play one but it is not their first go to instrument. It sold for $2600 in 1991. Moog theremins evolved over time to be better and then what we have today? Being old makes it rare but definitely not better.

Put it on eBay and see what happens. Posted long enough time will tell you what it is worth.