I've thought a lot about this question. And having had upwards of $400,000 in gold and silver investments at one time I do have some experience.
First of all, my opinion is that an "investment" in gold and silver is an INSURANCE POLICY. You needn't look far to find good reason to buy insurance. Indeed you could argue that the USA has repudiated its sovereign debt four times in the past. Here's a good article at CNBC:
https://www.cnbc.com/id/43140915
You also needn't look far to find examples of first world countries with massive currency issues. In 1998 the banking system in the USA nearly failed as the result of the implosion of the Hedge Fund Long Term Capital. In 2008 in Greece you were limited to withdrawals of a few hundred dollars. At the same time, in Cypress the government essentially confiscated money in bank accounts. There are also many examples of hyperinflation too in recent memory: Zimbabwe (2008), Yugoslavia (1992-1994), Argentina, Venezuala etc. And how do you think the USA will deal with its massive debt (and most first world countries for that matter). They will monetize it via inflation. It's not here today. But it seems inevitable that it will happen. There is no choice about it. So you need an INSURANCE POLICY to hedge these risks. You may never collect on the policy. But if you need it, you'll have it.
So how do you figure out how big a policy do you need? If you have a significant net worth I would recommend 3% to 5% of your net worth. If your net worth is smaller or smallish then I would recommend a bigger policy.
And what should you buy?
Of the 3% - 5% I would suggest having a third of that in physical gold and silver and the rest in shares of either physical gold and silver trusts, or in mining companies (or, better yet, mining royalty companies). As far as the physical gold and silver goes, some "junk silver" is a good idea. You can buy it for very close to face value, and everyone knows that a pre 1965 quarter, for instance, is 90% silver. The rest I would have in gold and silver coins like American Eagles, Maple Leafs, Brittanias etc. Spreads over spot vary considerably, but if you accumulate your position over time it will even out.
I have nothing to sell here Richard so my advice is not biased by a desire to sell you something. If you'd like a more in depth review send me a PM.