But dollars bought on black market were not used for buying staple food or common household items, but generally for buying things (say, from foreigners, or in

But dollars bought on black market were not used for buying staple food or common household items, but generally for buying things (say, from foreigners, or in special Beryoska stores) that were not otherwise available in Soviet Union at all. (Mere possession of foreign currency was a crime, so dollars were not used in normal day-to-day operations). So the black market rate was heavily inflated and is quite misleading too. Purchase parity calculations for comparable goods available in both US and USSR make much more sense; although not simple, because of very different price structure. 115 roubles would buy 4-5 gallons of vodka, or ~25 pounds of good quality meat. How much this would cost in 2021 US dollars?