I think the "Change Look" option is just awesome. With this method you'd never have a "When your armor looks terrible but you have the best stats moment." But the problem is that it has a little 'bill' for it. I think it is not logical to add a price to "Change Look" since it is purely for cosmetic. A person who wants to change ther look might as well spend that currency to buy more gear with actual stats. So for this reason, to make this game and its customization system perfect the "Change Look" option's price should be removed to allow people to create their dream Knight, Samurai or Viking more easily and satisfying.
You could also just try and get the cosmetic with the stats you want, so far I've only changed the appearance of one item and don't remember what it costs. Though I like the look of the Nobushi which is my most used character hell my only used character, think all her cosmetic options look pretty sick.