Sure it is provided you don't want to improve the rest of your squad as well. At the end of each season you have retirees and players who are inadequate and get sold if you've been promoted and are in the champions league. It normally costs approx 15-20 tokens at the end/start of a season to add 3-5 players to the squad ready for the new season. In effect the game is asking for the same amount of tokens for a single player. You don't have the option of making an offer for a player on the mobile version and it is extremely rare that you get a player with less than 3-4 tokens bid - on lots of occasions you save 10-15 tokens and waste most of them because you get outbid. At times it is more economical to use your tokens to buy health or rest packs. There is no doubt that academy players are vastly overpriced in terms of the tokens needed to secure them.