For the lack of ammunition, I would suggest in purchasing reloading equipment and components.
A press, dies for each caliber you need or want, powder, primers, brass and bullets.
Oh, and you might also considere lead, melting pot and bullet molds.
Powder kept dry is good for long, long times. Same with primers and brass. I started doing that back in the late 80's. At that time, a typical 38 special cost about 10 cents a round if I recall. the cost of the components for that round were under 5 cents. To be more sure, I'd have to find the HD that has all those old spread sheets on it.
Just a thought