Jim, he is represented by a professional agent. You are portraying him in this thread and the Mercer signing thread like he's some sort of feeble weak sap guy getting massively abused by team.
If money was so important to Mercer, he could fight his side more via his agent and tried stronger stances and held out longer. He's not a poor sap slave to this process. At some point you have to accept he accepted this deal too and weighed in the options that were realistically in front of him.
12 million over 3 years plus the future leverage (if he performs well during this contract) to say he is worth a lot more than this one and can leverage that for UFA time telling NJd or others that he took a reasonable NJ friendly negotiation last time and expects this time for them to pony up.