We will never find out the true cost overall of Mangala, but it has to be in the region of £60mill-£70mill, including the transfer fee and wages.
Let that figure sink in, and just imagine a player/defender City could have bought for that kind of money. VVD comes mind straightaway.
If you want to include wages then Van Dijk cost about £140,000,000.
So make your mind up, was it wages+transfer fee, or just transfer fee?
Truth is, Mangala probably cost half your guess. 40m all in after considering his wages and loan fees paid by Everton & Valencia for half his time here. It's the price of doing business, every now and then you get a dud, not everyone can be as good value as Bernardo, Zinchenko, Jesus etc.