I start at $80 for a baby/twin size, and $250 for a double/queen, $400 for a King, plus materials and thread. (don't forget thread adds up!) Then I look at the pattern and if it is going to take a lot of time to piece, the price goes up. If the quilting design is complex, the price goes up. I also will attach the binding but I machine sew it. If they want it hand stitched I will sew it on, but they will have to hand stitch it.
Having said that, I don't charge as much for close friends. But as soon as it gets to be "friend of a friend", then they are a customer, and the price reflects that. I always get the customer to pay for the fabric up front - even have them order it online and deliver it to me.
After all, quilting is my hobby love. If I start making it a job, then it's not fun anymore.