They didnt have anyone over a barrel. He had a choice. A FREE choice. He chose to accept that quoted price.

As others have said. When you buy something in a shop at x price. You dont decide later that day you got ripped off because you could have bought it cheaper 5 minutes down the road.
Again, you made the choice to buy it there and then.

Or same as main dealer servicing etc. If you choose to pay £100 p/h for work on your car...well, clearly you're mental. But some people choose to do it.
No sense crying about it afterwards when you know full well what you're getting into cost wise ( incompetence levels are another argument though )