Question regarding paint quality?

My question is I understand that one of the more important ingredients in paint is Titanium Dioxide, and than when I ask some of the paint store people at Benjamin Moore they state that their paint has a greater percentage or higher grade and this which leads to a longer lasting paint. When you read the spec sheets either on the can or internet other ingredients are listed as "Proprietary" so it seems that the consumer doesn't have formulation standards to make an informed buying decesion other than trust that the $40 paint is better than the $20 paint.