I know exactly what you mean. While I have never made a quilt for someone, I use to do upholstery and make draperies. People would say, "I can go buy a new sofa for that much!" I'd say,"Yes, you can. However, you are not comparing apples to apples. You have a very heavy frame and are getting designer fabric. You will get a pressboard/cardboard sofa w/inferior fabric...."
I finally had enough. Then people were like, where are we going to get our fabric and work done now that you are closing?!?!! HA!~
Just keep going. Keep giving quotes. I found that educating people helped a little. Maybe make a sheet up of about how many hours it takes, what the materials cost,etc. break down the price that you give them so that they see where their money is goign. Hope it helps! Sandra