Halfway through typing a huge answer to this, decided I couldn't be fucked, so just going to say, yes it is.
It really isn't. There's enough cheap bargains and enough expensive flops to show that. The fee is based on a lot of things; the financial position of both clubs, the importance of the player, his nationality, his age and so on.
A club in Romania is going to sell the exact same player for a lot less than a club in England would.
If a player is English his fee is going to be more than if he was Romanian.
Smaller clubs will always milk every penny out of United, Real Madrid etc because they know they have cash to spend.
So, no. Fee isn't strictly related to quality.