There's so many gold bars hidden out in the wild that money really doesn't even need to factor into it, to be honest. I've made over $7,000 this play through as each bar you find out in the wild is $1,500 a piece and if you've got a guide they aren't hard to find. That being said, Higher honor leads to massive discounts, (50% at the highest level) much more valuable loot off corpses, clothes that you need to have a high honor level in order to get, and general changes in dialog that make it worth it, especially towards the end of the game, and in particular the ending itself.