For me what separates Goretzka from other very good Midfielders is his aerial ability. But he will rarely come cheaply. And I rarely see him available in the first season.
I think I paid 20m+ for him in season 2 or 3. He was worth every penny. But if your starting budget is not that rich, you will likely get better bang for your buck picking up a Lucas Romero, Youri Tielemans, Roberto Pererya, or Lucas Silva instead.
Of course the best midfielder in the game is still Pogba and he is insanely expensive.