With this tip, you should be able to make 1g every 5-10 minutes

Location: Catacombs, Tarantia Noble District

Required Level: 66/67++
How it works:

Enter instance, Take first Left, then first Right, then next Right.

There is a Melee Boss. In the same room there are two Explosive Urns.

1. Get aggro from the boss, take him to the first urn,
2. Destroy the first urn, this will take the boss to 25% HP
3. Take him to the second urn,
4. Destroy it, this will kill the boss.
5. Loot the boss - hr drops between 5silver and 15 silver.
6. Leave the instance
7. Invite someone to your group
8. re-enter instance
9. Leave group

(note: steps 7-9 resets the instance)

Rinse/repeat