I probably rotate between five or six theatres, depending on what I'm seeing (big budget action film, small indie release, classic film showing, etc)
Low is $4.75 for a Tuesday showing at a real shit hole near me, high is $14 or so for a ticket to an AMC theatre on a weekend night. Don't bother with 3D and liemax usually but those range from 16-20.
I usually end up going to an older one near me that is $7 for matinees, $10 for nights, and $15 for 70mm.