One should never answer this type of question again on this board. People do want advice, but as long as you don't step on their brand it's OK.
You would think that stating paint from a Paint Dealer would be your best buy and best direction to go. This is definately what I would say.
As a paint contractor, I get asked all the time what paint will you recommend on my home. I reply: one of these three, SW, BM, or KM. They say good. Now, wonder if I had said, Wal-mart, K-mart, or STop and Go brand? Do you think i would contract that job?
One thing for sure in the paint industry, the higher the price of paint, the better the quality and tech assistance when a problem does occur. I had a problem with a paint coverage on time with SW. They came out with testers and observers that day to assist me. Do you think that Wal-Mart would do the same?
I have a $1800 spray rig, do you think that I would run $8 a gallon paint through it? I doubt so.
I have always subscribed to this motto: "We do not argue with those whom sell for less, because they know what their product is worth".