Ok, the Mystery Player thing was sort of a trick question. The intent was to unbaisedly gauge whether the disastrous-ness of Andruw Jones' contract outweighed the goodness of the Manny acquisition, both in terms of output and salary. I took the weighted average of Andruw's and Manny's 2008 stats, ratcheted it up to 530 at-bats to simulate a full season (my ballpark guess at how many AB/year they averaged over their careers), and then averaged the salary element of their contacts ($18 million/yr for Andruw, essentially $0 for Manny).
Anyhow I don't claim this reasoning is perfect (for one thing, the goodness of Manny's contract was in effect for only for 2.5 months, whereas the badness of Andruw's was for 2 years). But through the exercise I did learn one thing: Mandruw '08 looks a lot like Pat Burrell.