I've found Winchester .45 ball ammo to be the cheapest in my area if purchased by the 100.
I buy Wolf and American Eagle ammo from the local range if I am out of Winchester. There is Blazer ammo and I have used that before. Blazer ammo isn't always wrapped in a traditional metal. I have shot these and Will Not use aluminum or steel jacketed rounds anymore. I had to many stove pipes and oddities with non-traditional jacketed rounds.
So for now it's Only Brass... No steel or aluminum.
I have been warned about CCI Speer ammo