To be honest, I enjoyed the game more when I didn't buy any either, just farming, at least my team then didn't become overpowered in terms of power training and walking the league in the last 5 seasons and winning the Champions League in the last 5 seasons also. I mainly walked a few of the leagues in the earlier levels of the game due to the sheer number of inactive teams there was and there was nothing to compete against a 5* team, but the game is best when there other teams that are able to compete against you for the trophies rather than beating teams that are 10-15Q worse than you nearly all the time.