Never give a separate price for materials and labor! It invites people to say they will buy their own materials/supplies and go get the cheapest they can find that you then have to work with. Only once did I agree to make some bridesmaids dresses for a "friend" at cost + labor. I was very specific the kinds of fabrics I worked on and said I would go help pick out the fabric. The next day I was brought the cheapest, worst polyester satin you have ever seen. Never, ever again - it was miserable to sew on.
I only sew for pleasure now, but my advice is give one price for the purse, quilt, or whatever. No store I know of tells you what they had to pay and then separately tells you the cost of their labor/profit. Why would you quote 2 prices unless it was some unique circumstance?