Just my opinion, I do commercial quilting and occasionally construct a piece for someone. I use to try to compare my prices to others to make sure I was charging fairly to the customer and myself. Finally realized we all have our own reasons for what we do and I stopped worrying about others in this respect. I charge retail price of fabrics, which the customer can choose. I take their choices and put them into the quilt so they look their best. They choose the design. (I own a small quilt shop so I make a little on the fabric and pattern). Then I have an electric clock that I plug into a switch or extension cord with a switch on it - Every time I work on the quilt I turn it on, at the end of the time I log the time on a clip board. I also put the materials on the clip board, When the top is done I add up the hours piecing and multiply by $10 - that is low for my time, but that is my minimum. Then I quilt it to their request and charge for that as if they had brought it in. Figure to the clip board. .10 an inch for binding (that includes making the double fold bias and applying by machine then hand stitching the back.) Add it all up and they have a total. I don't give figures in advance because I don't really want to make quilts for others so if they want me, they understand it isn't going to be cheap. Average queen will cost them $500. They are purchasing al la carte and they should expect to pay for it. Also if you charge in stages, it won't hurt as bad when they pick it up and if they back out midstream at least your fabrics, pattern are covered. Make these nonrefundable if they won't pay the labor to the point where they decide to stop. ( I was bit by this when someone changed a color palette for the room it was being made for.
Don't work for free, you will soon resent them and the work. If you can't make enough on a whole project, specialize, charge fairly for it and love your work!
Oh yes, forgot. I won't make a quilt without prewashing and starching the fabrics - so add $1.50 per yard for this part of the project. I don't want them coming back the first time it is laundered and have to refund them because the fabric faded (I don't care what you are told - quality fabrics do fade or have a lot of excess dye in them and they definitely do shrink. Expect wide backs to shrink 3 - 4 inches in width and 1 inch in length)or part of the fabric shrunk and others didn't. Muslin shrinks lots more.
We test all our fabrics for color run and shrink.
Please forgive my lengthy explanation.
Sally