im no expert on this but you might get a few quid for him, have a look in the noob bible i think there is a chart there what tells you the values of players, remember players seem to be worth more when they have not had a trainer
he has 22 potential points from his first trainings, without trainer, you might get 1-200k maybe? but that is the max I'd say, you can even get a few 10s of k