I've no doubt it is possible. I would just be surprised if we spend that much on one player this season.
The reason that it would surprise me is that we need many players. Lets assume, for the sake of argument, that the club has £3 million to spend on trasfer fees. I wouldn't be surprised if the club spread that across three players. To spend all of that on transfer fees for one player is a risky strategy. If the player is a dud, doesn't settle or is problematic then all of that money is gone.
I may be wrong. Last year I thought the idea of us signing Niko Kranjčar was unrealistic.