With 2/3 of the outfield (Benge & Ewing) being young , cheap & under team control for several years to come, they are worth holding onto. That should free up some money for the Mets to get starting pitching, a first baseman, and a quality RH outfielder that can DH/platoon or possibly allow Ewing to play second more.
More and more, I am starting to believe that Bichette will return to the Mets next season. Noo one is likely match his current salary.