One thing I'd imagine is "What if a game introduced when five-digit cars were the norm was introduced during the '70s or '80s when four-digit cars were the norm?" is how certain pricing games designed for five digit prizes could work back when there were just four. Seeing how the Cover Up game from the Romanian version in the Pricing Games Around The World thread is only played for four digits, it makes wonder how good certain games that always have had a top prize of at least $10,000 would have worked with just four digits. I could even include Golden Road since in 1972, prizes in the $7,000-$9,999 range were still very nice and could have included Lincolns, Corvettes, and Motorhomes (just watch syndie LMAD from the early '70s). Similar to Make Your Move today, you'd start with a two-digit prize, then a three-digit one, then a four-digit one, with the tens digit instead of the hundreds missing. The base item would still be in cents, although it would be easier to guess the second and third prizes as there would only be two choices for the second prize and three for the third-digit prize. Sure, the current Golden Road is harder, but I still would see that the leap to five-digit prizes, despite the added difficulty to be a great step, although there could have been a transition of the other two prizes for several years until the $20,000+ prizes started to become common starting in 1983.
I could imagine Stack The Deck having just two free number choices instead of three, with one fewer digit among the number choices to guess, along with Split Decision having one less digit to choose from as well. Gridlock would not have the free first digit, while on That's Too Much!, there would be multiple choices within the same thousand (i.e. $6,000 $6,500, $7,000, $7,500, etc.) As it is, some of these games could work on the Live versions where the budget is smaller.