I bought a used set of Gefells with bodies, sold them, and bought another. The way the sellers had them priced, the caps are the valuable part, so the bodies were $800/pair on the first one, and $600/pair on the second round. Caps were in the $800-900 range for a pair. I think these prices are a little on the "low side", in both instances I thought I got a good deal. For instance I had a set of bodies with black hyper caps, and silver card caps came up, which wasn't what I was looking for, but the seller offered them to me for $800 because he was anxious to sell. I don't think that sets "the going rate".
In both instances they are "close enough that I can't tell the difference" as far as matching goes.