So I got a call from the secretary of this GC I work for asking how much I would charge for an electrical inspection for a commercial property they are looking to buy. I told her I'd charge $300 or less depending on how much work was involved. So I did the inspection and didn't find too much wrong except the fact that the place was a auto dealership and they are looking to sub divide it into individual spaces so nothing was going to be useable. The 240 volt three phase bastard leg service also was going to be a waste and needs to be a 208 volt service with 6 separate meters. All in all I advised the owner of how to properly go about this building if he did purchase and he totally agreed. I sent him a invoice for $150 for my hour. He sent me a email stating I forgot to tel him that he was going to be charged. I replied that his secretary forgot to inform him that I told her there was going to be a fee for my service. Obviously he feels this should be free. I might get a nice job out of this but it's a coin toss. Not sure how I should respond. What would you do?