c-products usgi mags for 5.99, yes $12.95 (any quantity) shipping. So 10 mage are only $72 shipped.
https://globalordnance.com/new-usgi-aluminum-30-round-ar15-magazines-with-anti-tilt-follower/
https://globalordnance.com/new-usgi-aluminum-30-round-ar15-magazines-with-anti-tilt-follower/