The first is that as I've said in the past, except for teams where slightly increasing the skills of their players is very, very valuable, a level 7 trainer probably loses them money, since that money would be better spent improving their players via the transfer market
It would be ridiculous for a BB developer to say this, to compare this with stoei´s example, it would mean make a slightly better car, price it higher and than say the higher cost isn´t worth the prize... who would buy this car??