I meant priority should be given to players having higher quality rating (in case you have misunderstood).
For e.g, consider 2 players A and B in the transfer market.
Player A: 4 star with special ability
Player B: 5 star without special ability
Usually, Player B should be given preference.
Consider another player, C, which is 4 stars. Training him to 5 stars should be given priority rather than giving him a special ability and let his quality to 4 stars. If the user can afford both, then he should train for the special ability first.