Channel Hop: The original series moved from ABC to NBC in 1957.
No Budget: While the 1970s version prided itself on its incredibly lavish prize packages (early episodes contained two Porsches as a prize), the 1980s run often went to the opposite extreme, sometimes awarding only one or two appliances as a "good prize". The cars were cheap and rarely won, and the producers froze the jackpot at its minimum value of $20,000 four days into taping after someone found the check early on. Further, props and sometimes entire skits were recycled from the 1970s version on occasion.
Screwed by the Network: As Geoff recalled years later, the 1973-77 version had actually gotten a fifth season. Around the time Season 4 wrapped, Barris told him about a skit idea for the new season: the contestant would be shown an expensive car but, after she calmed down, Geoff would reveal that all she really won was (for example) the steering wheel. Geoff thought that was far too sadistic and refused to do it...and was promptly fired, after which the show was canned rather than continue with another emcee. Geoff probably wouldn't have returned anyway, as he had a deal pending with Bob Stewart for what became Shoot for the Stars on NBC.