My buddies that sell at BJ are pretty convinced they get the most $$ there. Seems to be something rich guys are proud of - overpaying at BJ. I don't get it, but whatever works that way.
Haven't really looked at Pontiac vs Chevy / Ford. Agree with the above poster, I think its probably better for dealers than one off sellers. I do like watching BJ though because all the cars are no reserve.