When anyone asks me about making them a quilt, I tell them that I will give them a pattern (no one's ever going to get me to make a Double Wedding Ring!) and they can go to the LQS and purchase their fabric. Then I tell them that depending on the size quilt they want, it will cost approximately $100 - $200 for the fabrics, about the same for the quilting, and about $150 - $250 for my time. Needless to say, no one has ever asked again.
One person (not a friend, thank goodness) actually said that I must really think my work was something special to ask for $150 for my time. I just looked at her and said "You must have thought so, because you asked me to make one for you." And frankly, I think making a quilt IS special, and our work is worth every penny.
At this point in my life, quilting is my pleasure. If I started getting paid for it, it would become work.