Conspiracy lol, but I don't think it is so. Yankees always overpay less valuable players because they can. It's stupid, but they do this with all their players. Look at their bench, they're all overpaid veterans.
I read an article a while back about what makes the Yankees so good. And it is not just the buying of the best players. It's also the buying of the bench players. Ibanez produced so well in a lesser role for the team. Their financial flexibility allows them to do this.
In Mets' situation, if we sign Hairston to what he's worth this offseason, this would be a similar thing. We pay a bit more than face value for a lesser role, it fleshes out the team.