Sounds simplistic but it's smacks of the Munich strategy. Anytime you get the slightest opposition, rape that of it's best players and cake walk the league for another few years until it happens again. Juve's complete, unchallenged dominance of Serie A will just roll on for the foreseeable.
But yeah, fee's have gotten completely out of control. I'll preface this by saying there's a big differential in the finances of Utd and Liverpool currently, even if that gap is decreasing, so it's all relevant to either situation. But even if we where on a level financial playing field, there's NO way I'd want L'pool to go drop £100 million, just in a transfer fee alone before you add in his wages and everything else, on a player. And I really like Pogba and his potential. But that's all it is at the moment. Potential. I honestly don't see that much difference in taking the potential of a Can or a Grujic. They still need coaching up and have similar attributes and high ceilings. But you're not spending the farm on them. Again, all relative as Utd have the financial security to do this, but NO player is worth that IMHO.
Football has LONG been out of control financially but now it's out of ALL recognition.