Lol. if you charge £45 an hour then charge £90 not £150, it takes two hours max for an unskilled DIY, your skilled allegedly.
You think I dont offer a warranty, think again all work I guarantee for a year plus parts, I dont charge for travel time and I charge for an hours work, or I charge a price for a job, what ever the customer is happy with, thats why Im always busy and not sitting around waiting to mug some punter off the first chance I get.
Why are you charging 3 and a half hours labour to do a 2 hours job, as for london rates, they charge £45 hour in suffolk.
If your £75 hour, say so and the punter knows what to do. No I didnt thinks so, they would run a mile.
If I asked you to fit a set of springs and you said it will take two hours at £45 hour you would get £90 full stop mate.