Check out
Sportsmans Guide - PMC .45 Colt "Cowboy" loads for $17.47/50.
If you join their buyer's club, they're only $16.60/50.
Likewise, Winchester cowboy .45 Colt is $16.97/50 ($16.12 for members)
UltraMax .45 Colt in 500 round bulk order is $149.97 ($142.47) - about $14.99 per box of 50.