That’s right, a seller is offering an original Atari Pong C-100 game from 1976 on eBay. Unlike similar systems at the time, Atari’s C-100 featured “the use of a single chip that provided games with digital on-screen scoring and attractive sound.” Auction page. Click here for first picture in gallery.
As a matter of fact, other systems were still using analog or digital circuits using discrete components. Digial on-screen scoring would have required more components in the circuits, hence an increase of the retail price.