A good rule of thumb in just about anything you buy is you get what you pay for. I have never heard of Trinity paint. PPG also has a couple of other lines of paints that are not as expensive as Deltron, Global, or Nexa. There is a few reasons that these paints are less expensive. They put in a cheaper resin, leave out the uv, the solvents might not be as good of quality, the solids content will not be as high. These are just a few of the many differences. Check with your local paint stores and see if they can get you in the ballpark of those prices on that website. Any major brand is going to do a good job as long as it is applied correctly and will last longer on average than the cheap stuff. I hope this helps a little.
