http://www.espn.com/mlb/story/_/id/26306935/sources-angels-trout-new-430m-dealHe would get less than half after taxes...not clear if he is a NJ or CA resident...CA top rate 4.33% higher than NJ.
Of all the states with a baseball team Florida seems the best bet...no state income tax, and the average sales tax rate of 6.8% and the gas tax of $0.41/gal being consumption-based are less malignant than straight up income theft.