I charge by the square inch. It takes time to load a quilt, choose thread and pattern. If I have a quilt that is 60x80 that is 4800 square inches. My base price is 1.8 cents per square inch. That quilt is $86.40. If I meander, it will take me about 20-30 minutes to load, time to wind bobbins and thread the machine. Meandering a quilt that size may take an hour and a half. I am now into this for 2+ hours. That also doesn't take into account trimming threads, and keeping the quilt straight as it rolls. Was the backing ironed before it came in? Was it pieced? I now have wear on my machine, electricity, and I don't charge for thread.
How do you put a price on your time? This is the most stressfull yet most rewarding job I have ever had. What if the customer doesn't like what, did I choose the right color thread, and so on...
Thats my two cents of how I charge!