Having collected and bought lots of components way back when prices were quite cheap, I'm still reloading .45acp for about 15 cents a round.
Brass is mostly known once fired range pick ups from PD subguns and or other once fired bought for 1 cent each from an older retired guy that spent a couple of hours a day picking up range brass and selling it so he could take his wife out to dinner on Friday nights. Nobody picked up their brass on a range I used to shoot at and the ground was carpeted with it. A hundred dollar bill bought 10,000 pieces of good .45acp brass.
Powder is HPC-18 pulldown stuff from GIbrass in 8lb jugs (that was a long while ago) 700X, 800X, and a couple of others. More recently I bought some jugs of the BR-5 Jeff was selling. Loads well and burns clean and can be used for several calibers.
Primers, always bought in the 5000 count cases X many in SP,LP,SR and some SP. I used small rifle primers exclusively for all my 9mm subgun ammo for years and didn't even have small pistol primers on hand. Later I started shooting a bunch of 38spl so I broke down and got some small pistol primers.
Bullets are 230gr lead RN, Monatana Gold Bullet 230FMJ, 185gr jacketed HP and a few others bought in smaller lots as they appeared.