Maybe he doesn't know he is leaving money on the table....that is the problem with that bidding process. Unless you constantly update the "per head" price, you will never get it right. How much does all the stuff cost you on the job, including glue and teflon? Plus How much does all the labor on the job cost you, including the supervision? Plus How much does it cost for you to be in business on a daily if not hourly basis? Plus Don't forget a profit margin of some sort, that is why we do this right? All those things added together will give you your bid price. If you don't do it this way, you are probably guessing. If you are guessing, you are probably guessing wrong one way or another.