He faces a Faustian dilemma between quick money and his long-term career.
Faustian dilemma
idiomHaving to choose between an option that promises short-term gain with foreseeable adverse long-term consequences, and an alternative option with no short-term gain and possibly even short-term suffering, but promising an eventually better future than the first option.
The politician faced a Faustian dilemma: accept illegal campaign funding for an easy win or lose the election by staying honest.
The scientist grappled with a Faustian dilemma, knowing that releasing the unproven technology would solve the energy crisis while risking irreversible environmental damage.