Fortune-hunter

Someone intent to acquire a fortune by marriage. Someone who angles to marry a wealthy heir or heiress.

“‘A woman like Mrs. West almost always ends up marrying a series of pseudo-elegant fortune hunters, tango dancers with handsome sideburns, skiing instructors with beautiful blond muscles, faded French and Italian aristocrats, shoddy princelings from the Middle East, each worse than the one before. She might even in her extremity marry a man like Mitchell. If she married me, she would marry an old bore, but at least she would marry a gentleman.’”

Raymond Chandler, Playback (1958).