gathering skills will make u the most money over time than any other skill, that includes enchanting, minning + skinning can make u tons by just selling the things on the ah in stacks, i know a few lvl 40-60s who are skinning and mining and can make tons with just going out and getting a bunch of things from it and selling, the leather, hides, ore, stone, gems are allways wanted, so actually gathering skills are actually better than combination of both. but, if u want to be able to make ur own gear, depending on class, go minning/blacksmith or leather/skinning, just if u go two gathering, u should be able to make the money to buy what u want, if its in the ah