No need to spend anything on that man, simply sign your free academy players, train them to 4 or 9 ending quality(ex 34 or 39Q)
and then sell. If you'r on higher level you could also train them up to 1skill point away from next star( now also 2 points away playrs show on negotiation ? Corect me if im wrong.) and then wait for someone to place a good offer for your player.
By good offer i mean.. anything between 3 & 5Tokens is good offer. more than 5 is instant sell if you don't need that player( the case of free agents).
Hope i was clear enough. If there's anything else just ask