This question should in my opinion go to manufacturer. In other words: how much skilled gun smiting hand work goes to make barrel universally usable on all actions of same line of rifle? And are these barrels finalized by cnc machines, or human hand? (I do not know the answer, but maybe we should look in that direction) I know that many good combination guns (or lets say double barrel break action firearms) when buying spare set of barrels, the manufacturer recommends final fitting to be done by factory. I believe that final product is total cost of production where human specialized work hours are good part of cost, plus brand name, plus materials. So, how much cost to produce such barrel? When checking the price range of some makers, like Sauer or Mauser: sauer 101 / like mauser m12 will be in lower price range, when compared to sauer 202 (404) / mauser m03. The difference in price from lower to higher end, goes greatly to additional feature - changeable barrels. So this is additional feature that - we need to establish how much this realistically costs to get idea if price is reasonable.