If you can afford it, it's cheaper to buy 20 coaching in all areas (except Kicking) all at once. Kicking is not really needed since you likely won't train more than a couple of kickers and they don't need to be trained high to be effective. If you buy coaches a bit at a time, you will pay much more in bonus money overall.

OK, thanks for the advices... I built fitness center and hired coaches for attacking, defending and fitness since I don't traing tactical.