So the question needs to asked... what is Harper worth? With Trout being the comparison as he's making 33.25 M a year over the next three years how much more value do teams put into the Bryce Brand? Also, with only three years remaining on Trouts deal what do you think will happen at the end of the 2020 season with him and the Angels?
There is no way to know what will happen with Trout in 2020 simply because there is one more CBA to be agreed upon before then. The whole environment can change in terms of what the constraints are. As far as Harper is concerned, I don't want to be trite in answering your very reasonable question, but Harper is worth what someone will pay for him. My point in the piece is to address the demand side of the curve, i.e., that the competition for him will only be strong if his price is reasonable, otherwise he will turn out like Pujols in that no one (save the Angels, who were stupid about it) will be willing to pay $40M a year and tie up their payroll. It almost doesn't matter how good Harper is; there is only so much that teams with brains -- and, as I pointed out, the need to UPGRADE -- will pay to enhance a single position.