Once fired 45 ACP brass is fairly easy to find and is a bargan compared to new brass. You will have a hard time finding once fired 45 Colt brass. Seems many 45 Colt shooters also reload. I highly recommend Starline brass too. It's a bit cheaper than other brands and the quality is better. A bag of 500 should last you for a long long time.
The Starline prices look good but I am thinking of waiting until the next gun show here in PHX and buy 250 rds "Factory New 45 Long Colt 250gr RNFP" for about 72 bucks from Miwall Corp. Have bought a bunch of ammo from them and never had one refuse to bang yet. Will then have my own once fired brass and have had the fun of doing the once firing.
BTW. How much brass and or ammo is "good" to have on hand? I get to the range about twice a weekand shoot up 200-250 rounds max per trip of various sizes. It looks like by reloading and being able to expierement with various weights and loads there is a potential for loading and keeping on hand a lot of rounds.
I have about 300 rounds of 38 special and about 600 rounds of .357 magnum right now. I also have about 1100 rounds of .22 lr and 300 rounds of .22 mag. I pick it up whenever I find it on sale. Mostly Blazer and American Eagle. As you know I don't reload yet. When I start I'll probably keep around 300-500 rounds of each caliber I shoot. Then if I feel like shooting a few hundred rounds on a whim, I'm all set.