It's never nice when you're with someone and they're not happy about things. There could be a variety of reasons why he cursed because he thought the movie prices were too high, and it's worthwhile to consider what these could be.
From your question, I'm not sure what was being repaired, but he obviously wasn't very happy about the cost! Could it be that he is a little short of money lately? Money worries are a terrible thing to experience, and can lead to depression. If that's the case, it might be worth forgiving him for being a bit tetchy.
Another reason could be that he's stressed about something else in his life at the moment. Can you think of any issues that might make him a bit irritated? These things tend to spill over into our everyday lives.
Alternatively, he could be "one of those people" that finds something to complain about in everything, including the cost of things. Cinema prices have certainly gone up over the years, but it's hardly worth cursing about!
What should you do?
If it's a one off occurrence, I reckon you should just give him the benefit of the doubt that he was simply having a bad day. If it continues like this over a longer period, however, you should speak to him about it and try to find out what's going on.
If things don't resolve themselves, and you're really unhappy about it, your best bet might be to go to the cinema with someone who actually wants to be there with you, and isn't bothered about the few quid it costs to go! I hope you get things sorted soon!
Here's a little video that talks about the stress of money worries: