There are seven (7) chests per treasure room (so 21 plus the 4 hallway chests). This is where the bulk of the gold will be found.

Where a map like Elite Rahabkor will have a minimum base gold of around 3500, a max of around 105k and an average of 7k - the Arcane Catacombs have a min of 7200, a max of over 200k and an average of ~9k base gold loot.

The amount of time it takes you to complete the Arcane Catacombs is a huge factor.

If you only want the gold you need to clear the Catacombs as fast as you can clear Rahabkor... or you're gonna be out of luck ;-)