Small doom : gold $ silver.
Medium doom : Guns $ ammo.
THE DOOM : Food $ water.
The Apocalypse : doesn't matter what.

Nobody knows what kind of doom will be or if there will be only one doom or the doom won't evolve into a bigger doom or apocalypse.

My advice : have a piece of land, with a water source, preferabily deep on countryside.Have the guns and ammo already.Have seeds already.Have basic medicine already.

A small quantity of gold is useful in first stages of a greater doom, or if there is a small doom, taht world can recover shortly after.That gold will be changed for guns/seed/medicine/generator/ammo if the small doom becomes bigger.