I've owned several businesses, all construction related, and I've never had this happen. Did you give the guy a quote up front or just show up and start working? From the customers' perspective if the guy thought this would be a $90 job and you give him a bill for $900 I could understand him not wanting to pay. Now if you told him, this is time and material at $XXX an hour and I will be here all day, he should've had no complaints. Or better yet a flat upfront price.
