First, sorry I don't have much input as to your actual question-how much to charge. The usual verbage: give yourself a decent wage, keep track of hours - OR - supplies times three.
But, seeing your post reminded me of something I saw years ago, and loved. I thought this might give you some ideas to add to any you already have come up with.
http://www.quiltsbycindy.com/weddingdress.htm