While I can fully understand, and perhaps agree, with the argument that Bellingham is nowhere near being worth 150m (or even 125m) based on how good he is today and I dont think that you in general shouldn't pay record breaking fees for potential. Record breaking fees should be for players that are among the best (or the best) in the world in their position. But on the other side of the coin, if City have to replace Gundogan this summer and have identified Bellingham as the best long term replacement out there, who cares if he costs 60m or 150m, the club can afford it. People seem more obsessed with winning "the net spend trophy" and getting "great value for money" rather than winning actual trophies. We are not Brighton when you have to get the absolut most out of every penny to be able to compete. We already have a squad full of world class players which gives us the luxury of being able to pay over the top to get the player we really want, without having to settle with a second or third option who might be "better value" penny for penny. The club should worry about that when signing squad players like Akanji or Alvarez, not when signing a player they hope will be the heart of the midfield over the next decade. If Bellingham signs and stays here 10+ years, nobody will sit here in a decade thinking "we really should have paid 80m tops for Bellingham back in 2023".
If we get Bellingham, great, if we don't, we will find someone else. But its not like I would open a bottle of champagne if we would sign someone like Mac Allister instead thinking "wooohoo the club saved 50-70m on getting him instead of Bellingham what a deal" (even if I think Mac Allister would be a great signing too). What I care about during the transfer windows is the club getting the players they and Pep want. Not about winning arguments with rival fans about which signing is the "better value for money". As an example, I would rather have a 100m striker scoring 20 goals than a 50m striker scoring 18 goals since 20 goals is better than 18 goals.