2 things - low mintage, attractive, high-demand, perfectly conditioned collectible bullion. The other is numismatics.
I totally agree with you. No one should buy precious metals until they have all that is needed to survive such a disaster. I do, and I still had FRNs to spare. So I chose to start putting them into gold and silver so that when the recovery starts and fiat is no longer king then I will still have something of value. I repeat, do NOT by PMs unless you are already prepared to survive any disaster you anticipate (some don't anticipate any and so have no need to prepare). Have all the food, the medicines, the power generation and the ability to grow your food that you will need before even thinking about buying an ounce of silver.
A sterile surgical kit or 2, any 'chalky' kind of medicine you might need in the next decade after a disaster. A group of natural medicine seeds you might need to grow in the future and a book on them If you have non-threatening stages of disease, ask the doctor for the slowest breakdown drug he would prescribe. A lot of tubes of Triple antibiotic ointment. tape, curved needles and nylon thread, case of Walmart 91% isopropyl alcohol ( not ethyl or you might drink it all, the first time you have to remove something from someone's body). Buy a couple of dozen of the hand squeeze generator LED lights ( no batteries needed) at the 99 cent store. Your choice of water purification chemicals and a filter for the storage bottles. Spend all of your PM in the first few months as after that the above will dominate. A single aleve pill may cost a ASE , 20 rounds of hand gun ammo an AGE. A Human Anatomy book would be good ( No you can't depend on WiFi if you have to cut into yourself , family, or neighbor and not sever their femoral artery or other needed part. Wow , never knew survival could be so complicated.
All things considered, an instant transposition from ground zero to whatever afterworld there is or isn't might be preferable to "living", if that's what it could still be called, a "life" after a nuclear or other apocalypse.
Collect because you enjoy the hobby, and if you make money at it down the line, that's icing on the cake. Don't go into this expecting to be rich, but if that happens then it's a nice bonus.
"20 rounds of hand gun ammo an AGE" If that turns out to be true I am going to be a rich man, lets get this zombie apocalypse started.