Buying clubs get all the stick and deservedly so. Coz often like PSG just did, they put up an amount that can't be refused... I.e the buyout clause (something meant to be so ridiculous that no one should pay it). In the absence of that, they pay over the odds so much so to make it silly for the selling club not to agree.
Once that happens, other selling clubs aren't going to sell for peanuts when those teams who are willing to throw excessive money around show up.
Monaco selling us Mendy for 49 million is one of the best examples of that. I can bet my mortgage that price changed after we paid 45 for Walker. Coz no way on earth does anyone at Monaco think Mendy is worth more than Bernado. Nor Lemar.
But at the time we scooped Bernado for a fair price, the big money boys (us included) hadn't started throwing silly money around yet.
The moment "we" started doing this ( and by "we" I mean the four big spending market setters in PSG, Real, United and City and their Minor cousins, Chelsea, AC Milan and most of the Prem teams in general) Monaco quickly readjusted their pricing to match our thirst. Lemar is now an 80m player and and Mendy a 50 mil player.
So yes, the problem is with those who buy at exorbitant prices. As sellers readjust their lenses to their spending. No way PSG get Berchiche for 11m if they had paid 196 for Neymar first. No way.