So wait, that means USSR had no coin valued at less than today's $1.5 by purchasing power (assuming the 1/2 kopek coin existed at the time)? Interesting.
Let's compare it using market tools. The black market exchange rate was about 5 roubles for one US dollar in late USSR (official rate was about 60 cents for one rouble, but you had to be an elite to use it, and even then, in very small amounts) - you get up to death toll if they catch you with dollars, but that's another story.
So 1 kopeyks in USSR was about 0.2 cents, and inflation calculator will tell you that would be about 0.6 cents in current value.
1 kop. was a small amount of money kids would often play with (you could buy a matchbox with it -- was its standard price!).