Grealish went for 100 mill and that has adjusted the market. Lazio can hold out for the very best price possible or simply refuse to sell the player. Actually Savic gets linked with moves away fromLazio every summer but he never actually leaves. Maybe the player is very happy with his life there, he is 27 and for a player of his ability not to have left there until now when every top club in the world has been chasing him shows it must be a combination of his contentment there and his club's determination to keep him.
To the contrary, I'd say it's adjusted the market in the sense that everyone and their dog thinks City grossly overpaid, and it has confirmed, this shouldn't be the going rate. Also, the 100m wasn't his market value but instead his release clause.
One of 3ish clubs in world football that has no limits on their budget, outside of pretending to follow FFP, saying fuck it, we'll just pay the release clause, doesn't set or even adjust the market. Unless one of those 3 clubs come in for the player we're talking about, AND absolutely, categorically want this player no matter what, as seemed the case with Pep and Grealish.