Don't forget that coins can be bought it 1/10's and 1/4's, so you don't necessarily have to trot down to the coin shop with many thousands. Some coins have extra collector value, but that shouldn't be calculated into what you actually have, only what you have to pay. Kitco is a good online source if local sources are dry.
It isn't artificially high, it's artificially low, if anything. It was this high 20 something? years ago, and inflation hasn't exactly gown down. Ditto for silver. On ebay, people are sometimes getting $20/oz, when the market claims it's worth 12??
Other metals can be real short term and make millions if played right, like rhodium and palladium. Platinum to a slightly lesser degree. For example, palladium peaked at close to 580, and it was below 250 in 04, and sits again below 250. Now, Rhodium went from 600 something in 03/04 to... $10'000 in 2008!

Best thing to watch for sell and buy times is find a good source for international, central bank moves, and "plunge protection"-type schemes.