I'd like to revise my earlier answer. I was using inflation-adjusted gold prices, but not inflation-adjusted currency values. In other words, I was trying to buy 1980 gold with 2015 dollars.

But this still highlights the problem with this scenario: currencies lose value over time. They do this by design to encourage people not to hoard currency, but instead to exchange it for goods and services, which encourages people to produce goods and services. Because of this, any non-perishable commodity is going to gain value over time relative to a fiat currency. There is nothing special about gold in this regard.