I would say it depends on your armament. I have a bringumhome SKS and an AK-47 for which I have a coupla crates of ammo and extra magazines.
For 12ga, I have a case of cut shells made up, and a case of standard. About the same (a case of .22Mag, 9mm, .38, 44Mag, buckets of .22's) for...