A friend once reminded me, “always take a knife to a gunfight.” Sounds counter intuitive but hear me out.
Seriously though, a good knife is a real weapon even when the blade starts to dull. Find a smooth rock, invest a few minutes and you can sharpen that blade up real nicely.
Is storing stuff in a buried container a good idea? Yes, provided you get a decent container and you put the right stuff in it. Decently sized storage containers that can be buried range from less than $50 to $200 or more. As with most items, the warning “you get what you pay for” applies here.