You paid 6 tokens plus the greens in terms of resources.
I usually buy 90% 5star players, from TM with 1T.
So if you compare it, much more cheaper than the academy one.
So on the overall there are many factors if someone should indeed buy academy player
1. Academy player is fast trainer. Do you find fast trajners in your TM?
2. If tou find fast trainers, how much you pay for them , are there bid wars for them or you steal him for 1T
3. Are you aware of how to find fast trainers?
4. How many greens have you stacked up, do you afford to train a 4star player?
5. What team do you keep 5star team? 6? 7? It is different to train a 4star player to 6 than to 7 stars.