Gold does not change value, gold does not change at all.  It does not rust, it doesnt react with air water most acids, cant rot.  Even if melted it can be put back together just the same, this is its worth.   When the price changes it is the dollar which are moving not the gold because that bit of metal has done nothing from one day to the next where as the change in dollars based in politics and its debt and trade worth is substantial.

If they put dollar rates to 20% as they have in the past briefly then gold price will fall maybe half but this is not the metal being any less useful.   The point to buying gold really is long term it will out last the dollar regime.   They cannot afford 20% rates as all the debt issued in recent years is payable in the nearer term and the government cannot pay interest on it (without reducing their other budget costs like the worlds largest army etc), I dont think USA can afford 5% rates even.  
If or when inflation goes past 5% then gold will have a positive yield in comparison to money, which normally should be impossible as it does nothing and performs no business where as USA and its currency should be returning positive rates on its borrowings