Well so I have found out recently that you can do 3 for 1 tickets by combining CEA Card with meerkat movies and if the CEA card holder is a student you can add NUS for a further saving.
Even the CEA card on it's own is quite good, but of course you need to receive PIP, DLA or some other disibility benefit to get it as well as pay £6 for the year for it. Here is more information about CEA Card. http://www.hotukdeals.com/deals/carers-cinema-card-free-entry-for-carer-with-disabled-person-6-00-for-1-years-2419498
You can combine the CEA card with meerkat movies or the 1/3 off cinema ticket days that cinemas do (Odeon on Monday, Vue on Tuesdays). You can make a further saving using an NUS card for the CEA card holder.
Prices can depend on where you are located as some cinema locations are cheaper than others. In my area a standard ticket is usually around £10-12. But using the deals above can get you down to paying around £2 to £4 per person depending on the days and whether it would be 2 or 3 of you going.
I know Odeon and Vue accept CEA cards in combination with promotional tickets with no question. I'm not sure about others like Cineworld though, I heard that they accepted and refused them in the past.
As for NUS most of you regulars probably saw the NUS deal a few weeks back that you can buy an online course for just a few pound and then be able to qualify to buy an NUS card.http://www.hotukdeals.com/deals/become-a-student-get-an-nus-card-for-16-course-from-gogroupie-4-2614520
Of course don't forget you can get meerkat movies by just buying cheap travel insurance for a day on comparethemarket.http://www.hotukdeals.com/deals/meerkat-movies-2-for-1-for-1-70-2606380
Hope this helps!