If we remove game required gold for study, there would have to be another way to limit the skills a character studied. A level one character could study one parent skill. This would make how much you know be a function of how old you are, and how much you've done, instead of how much gold you have. I like the feel of this idea, and was surprised at the cool reception it got. This doesn't limit what characters can know in the long term.
Young units have to go out and do things before they can be advanced, multi-skill companions.
Gives players an incentive to cooperate rather than trying to study every skill themselves.