Dinan you pay for a lot of things, but specifically that warranty, CARB certifications (no worries with visual), and the Brand Name/Marketing, which bring pride of ownership to some. All of these hold a lot of value to some people. Dinan does tend to be more conservative, but they are also on the line if something grenades in your car. Neither Shiv nor Terry will buy you a motor if it blows up, Steve Dinan will. This costs a lot of money that neither Shiv nor Terry need to spend.
Yes, you pay more for less performance, but you get other things which are VERY expensive for a company to provide.
Some people on these forums just don't get it.
If you look at my Mod List, you will see I am NOT a Dinan Fan Boi.