I don't understand. If the source of Gold is the Arena, why would you need an Arena for Gold? There is an abundance of Gold in the game. The problem is when you're Ranking the highest Rarities of Champs and running the highest Maps, you're going to pay the most Gold. That will either require you to run more of the Arena to make more Gold, or choose wisely. It's simple budgeting. How much you are able to spend is equal to how much you're willing to work for and save.