That wouldn’t be as good for gold and silver dealers, though. :P
Personally, I think seeds are the best investment. That and knowledge of how to get and grow food, and other basic living skills. Even just storable food is good; food doesn’t really go down in value, so even if you end up eating it you’ll have spent less than you would later on.
Not that I don’t have a pile of ammo, but that’s just to keep everything else safe and to get meat.
Also, silver actually does have some practical use. High purity silver can be used to increase the effectiveness of some types of water filters. It can also be used to make colloidal silver, which is a powerful medicine. My dad stocked up on a small pile of silver wire for that purpose.
Personally, I don’t like monetary economies anyway, so I try to spend what little disposable income I have on things that will better help me be self-sufficient regardless of how the economy is doing (and I hope it crashes, for other reasons). My tribe and I will be fine no matter what, because that’s just how I want to live anyway.