The argument they're making is that because the original value of the dollar is worth X amount of gold, until the 70's (where we got off the gold standard), the "actual", gold backed value would've been a constant multiple of the price of gold today (since gold's value is stable under this assumption), and thus, the dollar lost a bunch of value.

i don't buy it, because the amount of possible goods/services purchasable today is much higher than back in the 70's.