That problem is usually repaired in one of two ways; replacing the hinge pin, or adding metal to the lug and refitting to the old hinge. I won't try to speculate as to price; but option one is typically the most expensive and most time consuming. I have had a couple of hinge repairs done by virtue of the second method, whereby a small dovetail notch was cut into the radius of the lug at t the hinge joint and a new piece of steel fit into same. The gunsmith then slowly filed the new metal addtion to fit the radius of the existing hinge pin until the barrels were again on face and fitted properly. In my case, the dovetail fit of the new piece in the lug was so precise that the joint was invisble with the lug suface polished. Also, properly done this method has no impact on barrel finishes.