I would take 3 times the cost of all of the materials or set your self an hourly wage. I suggest $20.00 an hour since it is your machine and the wear and tear on it as well as think of all the other equipment you use. So then keep track or your hours. A simple dress still will take at least an hour and a half to sew that is $30.00 dollars per dress. For me the average dress takes about 3 hours to make that is cutting, sewing and fitting. Good luck.