Why is it that the value of most guns is killed by a rebarrel even if it is a well done job?
I think only collector value is deminished. One needs to be sure to keep comparisons on a fair basis. OE finish is the first clue as to how much the gun has been used and we translate that into how much life it has left. Barrel condition is the major indicator of utility of the gun. It is, by definition, impossible to replace OE finish - refinish to OE standards is still not OE. Collectors prize OE condition and will pay for it. Shooters prize utility, but will pay much less than collectors because shootable guns are in much bigger supply than are collectable guns.
As a strawman, consider the value of a Purdey with a little remaining OE finish and smashed barrels (say run over by a shooting break/brake (sp?)). How much for it with the smashed OE barrels, with new Purdey's barrels, with OE quality replacement barrels, with lower quality replacements? The gun with smashed barrels is probably worth around $2000 or so. The new Purdey's barrels will set you back something like $20,000, $10,000-$15,000 for near OE quality "by another," and cheap ones can be had for $2,000 to $3,000. The rebarreled gun would probably be worth about 2/3 to 3/4 of the cost of the Purdey's barrels alone (not economical for quick resale), about the price of the "by another" barrels, and about the cost of gun and cheap barrels. The shooters out there want Purdey's guns, but they are mizerly about paying for the utility with the possibility of economic loss if resale is required. I'd be most interested in opinions on the foregoing strawman.