Today's New York Times reported that the Yankees hope to retain Bobby Abreu. Renewing his option will cost the Yankees $16 million. If they're willing to ante up that much money for Abreu, they can keep him.
On the other hand, if the new Yankees under the leadership of the Steinbrenner boys decides that $16 million is too steep a price for a player whose skill could be on the decline and let Abreu enter the free agent market, the Mets shouldn't pay him more than $8-10 million. Even that's too much for a player of his skill level, but then most of today's "name" players are overpriced.