Outdoorsman Sport Shop had 200 round bags of 45ACP this a.m. for $16.95, used brass, and they suggested checking back today on 9mm. Midway Usa and Mid-south (on-line)are on back-order as of Thurs.
If you are reloading common handgun calibers like .40 and .45 acp, and your main goal is cost savings, you will probably be loading range pick-ups. Particularly with a low pressure round like .45 acp, the same brass is good for many reloadings.
In that case, a reasonable price is "free."
If you are loading for some kind of precision requirement and have to get new brass, be prepared to pay. It is usually the most expensive component. Like anything else, you can save by buying in bulk, but it will still be expensive.
You can buy and sell brass by the pound, but the metal value of brass is not what determines its value to reloaders. A pound of once-fired Lake City .223 brass that has been prepped and trimmed and had the primer pocket crimp swaged out is worth 10x as much as a pound of range pick up .45 acp. They're both brass, and if you melted them down they'd be worth the same, but to a reloader there is a huge difference in value.
Generally what makes brass more valuable (not necessarily in order of priority):
1) a lot that is uniform (same head stamp, same number of previous firings)
2) fewer number of firings
3) quality of the brass (some head stamps are more desirable than others for various reasons)
4) unusual or hard-to-locate caliber
5) not beat up (for example, brass that's been shot out of an AR will be a lot more beat up and have more metal fatigue than brass that's been shot in a bolt gun)
6) closer to being ready to reload (has it been cleaned? Re-sized? trimmed? does it need to have a military crimp removed?)
As the economic crunch crunches, I'm becoming more and more of range brass whore. I collected about a milk jug's worth today, and I only shot 21 rounds of centerfire.