Thats not a bad point, we see price go up and down but since exchange rate varys its hard to work out the gain exactly.   This is where people lose money to inflation while they arent watching.    The one thing people could do is not use dollars in 2017 but dollars 1970 pre nixon standard.   Thats not exotic exactly, its just a reference to a set amount of gold which also adjusts in price.   The dollar used to have a worth in exchange, now we have the debt ceiling debate and QE buying gov debt, its possible dollar has no worth at all in the end (by the time you retire) so best to not measure in one thing only.