We are in the process of having an extension built, the builder has given us a price for the job, he has now realised that he has underpriced himself and has added more on top of the original. The problem is the builder and my hubby are friends so he was doing it discounted anyway but we have budgeted around the price he gave us plus a little more for extra (which we have the money for) but not the extra man hours he has decided to add on. We have paid him about 2 thirds of his bill but was holding the rest till completion. What would you d/say to him?