It’s a bit of a myth that he keeps replacing expensive players with new expensive players. Of his £20m+ signings which there have been 20 of, 14 are still at the club (with just 1 not having a significant role), 4 have been sold for significant profit, 1 is currently on loan and 1 is in jail. He has amazing transfer record at City and has wasted almost no money.It is a huge huge difference when 5 managers spend 1,5 billion or when one does it.
Also Pep has luxury to buy a player and if he diesn't work, he just bench him and buy another.