The Goonies --
(There is no Chester Cobblepot that was a lost treasure hunter)
They come across the skeletal remains of 1930s explorer Chester Copperpot and, upset that a supposed expert couldn't make it out alive, turn their quest into a hope to merely survive long enough to reach freedom. Their goal then reverts back to finding the treasure when they discover the bottom of a wishing well, which they could use to leave the caves. Instead of saving themselves, the Goonies - in a moment of clarity - decide to continue the quest for the treasure so that they can save the Goon Docks, even if it means risking their lives.