Paint quality can affect the finished product in many ways. Probably the most important factor is the longevity of the paintjob. Consider purchasing a car – obviously you expect a more expensive car to have more bells and whistles; but don’t you also expect it to last longer and age better? The difference is the parts used to make the car.
The same can be said for paint – higher quality paints use better, more expensive ingredients so they last longer. Other factors affected by paint quality include ability to cover, spreadability, and how much coverage you’ll get. As these go down, the cost of labor go up; so many times saving a few dollars in paint can cost you much more in extra labor.