Have you checked Rural King? They usually have one or more varieties on sale. Sometimes the small plastic ones are $2.99, but they have metal ones as well.
Pop on up to Indiana Army Surplus in Bedford ( INDIANA ARMY SURPLUS - All you could need from a surplus store ) . Great selection on ammo cans and a great staff to shoot the breeze with. I warn you though, if you start exploring the store, your wallet will get really thin, really fast.