So by your own admission he did a good job and is a good tradesman, yes? And you'd be happy to pay a good tradesman £150 a day, also yes? And you expected him to take two days, still yes?
Now maths isn't my strong point, but I think I see a slight flaw in your argument here...
I genuinely wouldn't get out of bed for £150 a day unless it was something I was seriously interested in. Like dressing Mila Kunis. With my tongue.
To some of us 150 is a good bit of money and helps a good bit especially when blowing so much money on a supercharger lol