fortune hunter

noun1

1. •
   A person who pursues wealth without earning it through labor, typically by engaging in ventures that are opportunistic, ethically dubious, or socially exploitative, such as entering into marriage for financial gain.

   • 101-year-old Rose (Gloria Stuart) returns to the scene of waterlogged hubris, where fortune hunter Lovett (Bill Paxton) is diving for diamonds. — 1998