I totally agree with Michellesews...We have all had experiences with cust that want a "show quilt" but do not want to pay. I won't go into my horrors story but it was like Michelle's. Ribbon and all.
Get a written contract and 50% deposit and bal pd when quilt is picked up. I charge .03 cents a square inch however this includes batting and thread. Custom starts at .05 and up.
I charge $10.00 a seam to piece a back. $5.00 to put on a sacrifice border per side if the back is too small. I use plain cheap muslin.
Never discount your work. They are paying for your labor, experience and time.
That cust knew what she was doing and has probabley done it to others.