Yes, there have been several instances where contestants on "The Price is Right" have won $50,000 playing Plinko. The first time this happened was in September 2008, when contestant Ryan Belz dropped all five of his Plinko chips into the $10,000 slot, winning a total of $50,000. Since then, a few other contestants have also won $50,000 while playing Plinko on the show.
However, it's important to note that winning $50,000 on Plinko is a rare occurrence, and most contestants typically win smaller prizes. The amount of money that a contestant can win on Plinko depends on where the chips land on the board, and the odds of landing in the $50,000 slot are relatively low. Nonetheless, the excitement of watching the chips bounce down the board and the chance to win big prizes have made Plinko a popular game on "The Price is Right."