Sounds like some folks I know!
Just go on and tell them you will be glad to do their quilts WHEN you have the time. Also, tell them that THEY have to go with you to purchase the material, the thread, and that there is no way you could possibly do the quilting yourself. Find 3 quotes for long-armers. Go with the highest as she/he will be the best. Don't forget to add the $15 per hour of your time and that your machine will need to be serviced and cleaned before and after doing their quilt. By now you will be into the many hundreds of dollars. Chances are, you won't be forced to do the quilt! This has actually worked for me...I only do quilts I want to do, when I want to do them.