We had this huge video rental store called Prime Time Video, and over the years I picked up all the Hannah Barbara games there on clearance when I had extra allowance money. I think it was around 1996, I remember specifically I got both of the Flintstones games in their front clearance bin. No idea what I had paid for them, but they were cart only I remember.
More on that, I used to rent Wacky Races, Jetsons and the Flintstones games from Blockbuster originally, but never saw them for sale, and it must have been pure luck that I found them at the Prime time video store.