Taking a family of 5 to the movies these days can easily run you $60-$80. More if you make the plunge for a 3D or IMAX film. There are a number of ways to keep cost down. Most theater chains offer rewards cards. Which offer free movie tickets, pop corn etc. The points can rack up pretty quick. Some rewards cards offer free refills on popcorn once you reach a certain level. Check you favorite theater or their web site for a rewards program and sign up.
Limit the amount of snacks you buy at the concession stand. Bring you own bottle water. Not big on water, just add a single pack of ice tea mix or lemonade or what ever you prefer. Stop by your local Walmart, or Target and pick up some candy. The same box of candy that cost over $3-$4 at the theater will cost about a $1 at these stores. You'll be glad you did and you won't have to hear, would you like the large for a quarter more any time soon.
Most theaters offer matinee prices before 5 PM. Which can save you $2 or $3 per ticket. Check the tickets prices of you favorite theater before and after 5 PM and plan accordingly. All 5 of us just recently went to the movies using the above methods and our price tag was just about $44. Enjoy your show!