Then Ammo seems the logical investment
@IsailedawayfromFR Ammo is an excellent investment. So are "buckshot" barrels for 12 and 20 gauge shotguns,as well as 28 inch full choke and modified choke. You never know what someone is going to want.
The advantage to stuff like spare shotgun barrels is they don't spoil,and you can coat them with a good thick coat of something like Vaseline,and they will last forever.
If you get any good deals offered on new or used rifle or shotgun stocks,buy them if they are for common/popular rifles and shotguns. Avoid foreign and off-brands.
Used ones are usually pretty cheap if you can find them. The price will definitely go up if TSHTF,though. Buy now,buy cheap.
Cases of 22 LR ammo are also a good investment.
Not to mention an old-time pedal-operated sewing machine for repairing clothes or even making clothes. Pretty much dirt cheap now IF you can find one,but priceless if electricity becomes rare or even occasional.
If you live near the water,fishing equipment is also a good investment.
Hand tools are ALWAYS a good investment. There has never been anything made that doesn't need occasional repairs.
Don't forget clothes and boots. Shoes are ok,but boots are better.
This list could go on for hours. LOTS of stuff you might want will be regional items,and useless in other areas.