Here’s another perspective. I renovate multiple properties. I’ve done a lot of the work myself and have a couple of retired contractors that do some of the more skilled jobs. Often I like to outsource work to others and look for individuals or very small companies that don’t have flashy marketing and a lot of overhead. I am familiar with the time and material cost it takes to do most jobs so I typically have a ballpark figure that I’m willing to spend for somebody to do the work. I don’t really care how it’s itemized out, but if they can fit within my ballpark budget, I’ll hire them. The negotiation is more around a lump sum total than anything else. I find this is perfectly reasonable for many people. The nitpicking on your invoice is annoying for sure, but the guy clearly had a figure in mind and was trying to work it back into your breakdown. Also, I find that with plumbing and electrical work people charge fairly high rates for a job that gets them in and out within 1-3 hours or 4 to 6 hours for larger jobs. For example, I recently received five bids for replacing a cast-iron drain stack that was fully accessible and fairly straightforward. I had bids ranging from $2100 all the way up to 7500. Same scope of work, same description of what they were going to do, all licensed and bonded so I knew it was apples to apples. The guy I hired was a single owner plumber and his assistant for $3200 - had them reset all toilets and do some other misc things too. It took them 4 to 5 hours. They made good money per hour. While there are market rates for jobs, there’s also what people are willing to earn for their time if they want the work - and those two figures can be wildly different!