Yes, even though Casey is under contract for longer, he has a much higher chance of tailing off. He just turned 28 (Oct). Prince will turn 27 next spring (May). So age also comes into play with the arguments of "can he do it again?" and "how long can he continue at this level?". If there are 18 3B that are as good or better than Casey, that makes a pretty small market for for buyers. But if Prince is in the top 5 1B, that makes a much bigger number of buyers that could upgrade their current 1B by obtaining Prince. If we traded both players this off-season and got a similar return, it would be a traveshamockery! (sorry, just wanted to use that word...) But seriously, if you were going to trade X (Gamel, Odorizzi, $10, whatever), would you prefer to get Casey for 3 years or Prince for 1 year (plus draft picks) in return? edit - clarified a few statements.