Buds Gunshop has used Glock mags for sale. I ordered a few G19 mags and got them today. They all looked good to go. One had some numbers engraved on the side form a LE department but the rest had little wear except one maybe needing a new follower.
Buds Magazine Blowout for Sale at BudsGunShop
Buds Magazine Blowout for Sale at BudsGunShop