I'm just starting a LA business and have taken several courses from different LA teachers--all encourage a written ticket so there are no miscommunications, especically since successful LA (I'm not there yet!) may have a backlog of quilts and details can get forgotten. They also discourage the customer from bringing thread because everyone's machine has it's favorite thread! And customer thread can get old if bought by the large cones--which can also cause tension problems. prices will vary depend on your local's typical price, but also the type of quilting--edge2edge or border2border(either as a panto or free motion) is typically cheaper, custom quilting will be more expensive. And of course dense custom quilting will be the most expensive. Brand/type of thread reuqested can cause a difference in price--for example, varigated thread costs more than a plain, poly. ditto with bat--wool or bamboo is more expensive to buy. also, a busy quilter asked to do a rush job may need to "jump" a quilt ahead in the line, work really long/late hours, etc. In a nutshell--there are so many variables that determine price and the type of job done, that a written document makes sure that nothing gets forgotten. I feel like there is so much for me to learn!