Gold Coins stats
if you like charts you'll like this one a lot
"And guess what: historically - that is since 1987 - gold price has virtually nothing to do with demand for US Mint coins (in terms of volume of gold sold via coins) neither in terms of levels of price effect on levels of demand for gold, nor in terms of rate of change in price effect on rates of change in demand.
Which means that at least in the case of the US Mint sales, there is no hype, and no madness. What there is instead, is a rather volatile demand with gentle upward slope imposed against a robustly positive exponential relationship in gold price:"