Give the person a breakdown of the cost in writing. The down payment should cover the cost of supplies you will be using. Are you quilting it? That's at least a $130 charge. You have to wash the tee shirts, another charge. Tell them to think about it and there is no rush because you have lots of other projects going. Chances are you will never hear about it again. My last write up for a nine patch queen size quilt with two borders with wool batting was $950 including the quilting and binding. The woman was a little taken back by the cost I had for fabric. I took the woman to the quilt shop where I bought the fabric. She was shocked at the price of yardage. She thought it would be about $30 for quilt fabric for all of it. LOL