A lot of his value has to do with his makeup and age, as players don't tend to be free agents at that time, as well has his elite defense.
I'm not saying he's worth that either, but if you go by WAR, and assume 1 win is worth 7M.....well, you get it.....it's a new reality - these guys are going to make bazillions. Batting average / RBI ARE outdated metrics though - the new stuff is better.
Wait until Harper gets 400M+
according to the war heyward is way better than barry bonds, jack clark and johnny callison were at that age...