@Larry - I do not anticipate nor prep for a doomsday scenario. I have no guns, gold, or collectibles. All I'd have of value in that event is some whisky, but I'd be too busy drinking it to sell it!
My problem with collectibles as an investment has little to do with where I think the country is headed. My issue is the volume of knowledge needed to successfully buy/sell. It's huge. I can tell you right now some of the posts in this thread convey ignorance around coin collecting that is commonly exploited by people on ebay and unscrupulous dealers.
Cleaning a coin dramatically reduces the value, for instance.
Buying on ebay? Watch out for chinese counterfits - they are getting extremely good, down to fake wear to produce believable grades.
Gonna pay a premium for beautiful toning? Better learn how to recognize artificial toning first. Your stunner might be worthless, because the toning was faked.
Think you can grade? The difference between a point or two in grade can be many multiples in value. Sure hope you can get it right and articulate why well enough to convince other buyers and sellers.
The list goes on and on. People that can sucessfully judge collectible coins get very solid salaries for the expertise. They are professional numismatists. That's right - the skills are so specialized, a person can base their entire career on them. There are even Phd's in the field.
Do you know how to store a coin without having it degrade with time? There is more to it than just popping a coin into an album. Start with encapsulation, then prepare to maintain a temperature and humidity controlled environment. Whatever you do, don't touch it! The oils on your fingers can etch the surface and drop the grade, or even worse, cause damage that makes the coin ungradable.
Oh, and the collectibles market is almost entirely unregulated...
IMO stay far far away, unless you love the collectibles as a hobby. In my experience though, most hobbiests put far more money in than they ever take out, because they become too attached to their collection.