Some films were officially licensed and were quite popular, such as Sun Valley Serenade, Some Like It Hot, The Sandpit Generals etc.
You might take a look at the chart here. Where there's only year, that's a Soviet film; foreign and joint-production films are marked with countries. As you can see, there are a few entries marked with США (USA). If you look by year, you'll find that it was roughly one American film per two years.
Of course, it was supposed that only ideologically safe films 'of high artistic value' could make it to the big screen. But it is said that personal tastes of the highest bosses of the Party and the State often affected the choice.
As to prices, the ticket cost something on the scale of 20 or 30 kopecks. For premieres the price might be higher, such as 50 kopecks. Films for children (including cartoons) were fixed at 10 kopecks.
The situation changed in late 1980s, when videocassette recorders became widely available and the state permitted some small business activity (the so-called cooperatives). Video salons became quite popular with their pirate VHS stuff, mostly action films, sometimes erotics or even outright porn. I suppose all these cassettes were technically contraband, but at that time the state preferred to turn a blind eye to it and just collect taxes (only porn was of course illegal and one might end up in jail for displaying it).
As to prices, I remember myself paying 1 ruble to see Jaws. That was quite a lot, enough to cover an adult's daily expenses (such as transportation, lunch, tobacco, newspapers etc.).