If you go online, you will find companies that make these types of quilts. They usually charge by the shirt, between $25 - $50, but this includes materials. Remember that you will also need stabilizer in addition to fabric, batting and thread. If you do decide to take this on, please get everything in writing, include as much info as you can regarding the materials used, estimated finish date, estimated final price etc.
And whatever you do, make sure that you get a non-refundable deposit so at least your materials outlay will be covered. State that the deposit is non-refundable in your invoice.