A person who does a task for the credit they hope to receive from it. E.g. A cop who doesn't call call for the absolutely necessary back up and tries to take down several bad guys on his own
John is always trying to be the hero, he's such a credit cruncher
Someone who is addicted to obtaining money and building wealth. A money addict and fanatic. Breadheads often work more than one full-time job, and some even participate in illicit activities to "obtain the bread".