ebony

An acquaintance just asked me to design and make a quilt for her husband. All she has is a picture of an item that she wants made into a quilt. She asked me how much it would cost to do this???? ah,??
Thinking on my feet (literally) I told her I would have to see the picture and know what size quilt she wanted.
Do you think it would be wrong to ask her to purchase all the materials and then charge her an hourly rate or set a ballpark fee--I would be making this quilt from beginning to end. She is not a quilter or sewer and has no concept of how much time and material fees are involved with quilting.
Several years ago I was making a pyramid quilt and she said she would buy it from me as she wanted to give a family member a gift. When informed how much I wanted for it she reneged on the sale.
Has anyone else been asked to make a quilt from beginning to end???? How did you charge???????