I bought a few "new manufacture" 50 cal ammo cans recently for about $15 each as I had a lot of loose ammo and small parts lying about. The prices have increased quite a bit but I could have waited to pick up a few free cans from a particular source). I used to get fairly decent used ammo cans for about $9-$10 each at a Army-Navy Surplus Store in SE Idaho (may check them out again in a couple months). I just noticed that SPG has a sale on used ammo cans listed as "good condition" for $8.99 each (member price) and if you use the $4.99 shipping (code: SH1675) it might be worth it for some here looking for some cans. I bought a few from them before and most were in what I would call "very good" condition but some of these are said to have some surface rust and/or stenciling on the side so who knows - may clean up nice tho.
As long as they seal it's what I use.
Anyway, just in case anyone is interested in some "cheap" ammo cans.
- Black Blade