How difficult was it to get, say, American music during this time period? I've seen the film Peresepolis, which briefly discussed how it was easy to get banned music in Iran during a similar time period.
Was there a large demand for capitalist goods at this time in the USSR? How would most contraband be snuck into the Soviet Union? How could a country so large possibly protect all of its borders from illegal goods being snuck in? Were there any particularly successful, notable smugglers during this time period? Was the situation similar across the Soviet Republics, or were there differences?
It depended a lot on the particular goods. Books and magazines were more controlled than luxury foods for example. Like anywhere else, smuggled goods were quite available if you could afford it and of course there was corruption among the police and customs officials. Sort of like how Cuban cigars were not legally available in the US. Different Republics were of course more or less uptight about smuggling (don't try to go over the Iron Wall) but dependong on the goods people found ways to bring them in, for example through normal travel overseas by pilots etc.
Iran is not really comparable to the Soviet Union, never has had a problem with "capitalist goods." The Islamic revolution in Iran was not anti-capitalism. During the war with Iraq and revolution naturally people didn't have a lot of extra money and the govt had imposed restrictions on the importation of luxury goods but like anywhere else, people found ways to get and pay for the luxuries they wanted. The problem was economic not political.