Even computerized machines allows for all types of quilting designs. We have a lady here that has one of the totally computerized ones and does wonderful work and she gets info from those that want it quilted as to what they are considering in pattern design to be quilted and goes accordingly.
Have you told them what type of design you want or have they asked? I'm assuming no. You should.
I know a couple other ladies you have longarms but not totally computerized and they do the same thing. They ask as to what design the person is considering and if they don't know they make recommendations.
As for price I've seen them charge anywhere from 1.5 cent per square inch to 2.5 cent per square inch and if anything is added they let customers know how much more it will be. Also depends on type threads is used.