"If you take a dime minted before 1964 [which contains 90 percent silver], it can still buy a gallon of gasoline today at roughly $3.50," he said. "But the dimes the government produces today with no silver content gets you 1/35 of a gallon of gas.
No, that 1964 dime at the gas station buys you 1/35th of a gallon of gas. No gas station operator is going to give you the precious metal value of a coin minted prior to 1964. You ONLY get that amount if you sell that coin to a collector or a precious metal dealer, and hope that the cash you get in return doesn't deflate by the time you get to the gas station (true, an unlikely scenario). What precious metal dealers are trying to get you to do is invest in their products by ginning up fears of hyperinflation. As I am fond of saying, if people are spending money advertising (or selling books) on TV trying to get you to buy gold and silver, its probably a bad time to buy gold and silver, but articles like this one help inflate the bubble.
In addition, the current "melt value" of a 1964 dime is $2.34, not $3.50.
The point of sale value of a dime is ten cents, of a quarter 25 cents, regardless of when it is minted. If you are collecting, its a different story.
Disclosure: I've been collecting coins since I was a teenager. I don't collect them as an inflationary hedge, I collect them because I think they're neat pieces of history. I dislike seeing silver coins melted down for their precious metal value, simply because I view them as historic objects.
UPDATE: I missed Megan McArdle's recent column. Now that is some world class stupid.