I experience this all the time and as a quilter you might as well accept and develop a plan for dealing with it. What I do is break it all down on paper. Each step - pattern, size, number of yards of fabric, cost per yard etc. You may have to guess at the number of hours you need to piece each block but then show the hours times blocks, cutting etc. Put in a line item for the batting, show the quilting as if you are charging a regular customer for the quilt they have made. Don't forget to put in a line for the binding. In our area they charge .15/inch for rectangular quilt and you supply the binding fabric. Add it all together and show them the breakdown. You can develop a practice estimate to show people. Queen size being the most popular and an average skill block quilt. Put the whole works together as a presentation. Don't faint. The price will drop your jaw. It's a come to Jesus moment for people who don't have a clue. By making the presentation folder you will stop the people fantasizing about giving an amazing gift for a little money. You also made a comment about it being hand quilted. If you like doing hand quilting, make a sample block or two. Hand quilt in simple and complex style - bill for both as you would a full size quilt. It won't take them long to get it. Happy Quilting. Don't sell yourself short, life is too short.