I do some work for a General Contractor that does mainly home remodels. He complanes because my invoices vary so much. I tell him you never know what you might run into when doing remodels. He wants a price list,but I will only charge T&M for typeof work. So I may end up dropping his work. I have enough work and can make more dealing directly with the customer.
The Golden Rule - "The man with the gold makes the rule"