If non-tox ammo cost $3.00 per shell, and premium lead cost $.30 per shell, and re-barreling could be done for $2,000(?) -- then one would have to not-fire 727 of the non-tox shells (or 29 boxes) AT GAME to cost justify the new barrels.
Most of us shoot 2 to 5 boxes of shells AT GAME per year, say an average of 3 boxes per year. In only 10 years of active hunting the new barrels would be cost justified.
Of course, one could instead purchase a FABARMS, CZ, HUGLU, Brittany, S&W, or other NEW SxS (safe with steel ammo)for less money.....
JERRY