The majority of the players who played against us in the 81 cup final were still at City that season. And whilst they didn't spend like they do now - the likes Asa Hartford, Dennis Tueart, Phil Boyer and Kevin Reeves were not cheap at the time. And it should not be forgotten that in 1979 City broke the british transfer record when they signed Steve Daley from Wolves for about £1.4 million
From his Wikipedia page: "His English record transfer to Manchester City in 1979 was later described as "the biggest waste of money in football history"."
They also lost £500,000 on Trevor Francis in less than 12 months. Bought for £1.2m in September '81 and sold to Sampdoria for £700,000 the following summer. They really were burning money at that time.
John Benson was the City Manager who took them down that season having replaced John Bond during the season. He was also the Wigan manager some 17 years later when the Gills beat them at Wembley in the league 1 play off final and John Bond was also there as one of his assistants.
Having looked at Francis' post-City record, I'm not sure that they got a bad deal when they sold him. They may have lost half a million, but he carried on for over a decade and averaged about 5 goals a season. One good season at Sampdoria and an injury record that would make Erik Lamela blush. Sunk-cost fallacy is something that we struggle with as a club and I think that they avoided it there.
Having blown a staggering amount of money on a load of rubbish (Kevin Reeves, Steve Daly come instantly to mind) Francis at least attracted a buyer for some desperately needed cash. Citeh were completely ****ed financially. The other wastes of space remained as unmovable as Vinnie, GKN, Big Vic, Rose, etc.