Young players overall are the best bang for the buck. If I buy am 18 year old fast trainer he will last for 6-7 seasons. So that is 6 seasons that I won't have to buy a replacement. It saves me tokens and money.

If you are short on tokens then sometimes it is better to get the old players for a few tokens.

One of the things that I did at start was to sell the young fast trainers for big prices and get a few old ones back. Now with the new transfer market I am not sure if that is a solid tactic anymore though.