Scaling quant/rarity gives more gold. If you have a decent character, consider replacing one of your flasks with a Gold flask.
Map runners are extremely expensive, so if you are having gold problems, you can pause them.

You can spec into `increase explicit map modifiers" nodes, but they can increase difficulty exponentially. Blue altars also have player buffs that increase quantify.

I have a dedicated tree for farming gold, but it requires a decent character to survive and be able to mitigate a lot of debuffs.