I used to pick up extra shotgun barrels at pawn shops! Back in the day, I'd come across barrels for the Mossberg, Remington, and the occasional Ithaca at pawn shops for $30-$50. Most I imagine were take-offs from folks who went and bought a brand new shorter barrel. I'd buy them and take them to my gunsmith, and he'd chop them to my specs (legal of course) and blue or parkerize and install the front bead for $20!