With the Krieghoff 16-ga. bbls. a good price today for a 20/16 bi-gauge set in excellent condition would be around $5500.00. Two years ago the same sets were changing hands regularly for $6500.00 to $7000.00---and sometimes for a little more. I know of a rare configured set (both bbls. 28", both sets of bbls. factory choked Q1/Q2, SG, SPL and DT's that sold three years ago for $8000.00.
I love my Repros---all 5 of them. My only ST Repro is undergoing a SST to DT conversion as I type this, which will make it the configuration I have been searching for for fourteen years.