Update (see pic below): Thanks to Gergy and Tscheuss who posted below: for characters with strong ranged power, the lava area below Lalait in final raid fight features rapidly respawning efreeti and fire elementals. Otherwise, the fire elementals in the final entrance corrisor respawn at a rate of about 30 seconds which gives a roughly average rate of 5 blue coins per minute (45 sec for 4 coins giving 15 sec to slay elementals). I just checked this 1/23/2016--the easiest difficulty is to run this Heroic Elite. Anything lower (HN or HH) will not guarantee a coin drop each time an elemental is killed. NOTE: bring evasion, fire resist and shield/nightshield spell for hard-hitting efreeti magic missiles.
Another option is to farm the coins in the corridor if you are a pure melee without any ability to make a temporary ranged power option (an epic character can do this through destinies and twists, though).
I farmed blue coins by killing the various fire beings in the entrance corridor and then exiting. This includes
- Several efreeti
- Mephits
- Fire elementals
What I found, rather interestingly, is that on heroic settings, the mephits do not drop blue coins; whereas on epic settings they do.
Conversely, on epic settings, the fire elementals only drop white coins, whereas on heroic settings they drop blue coins.
I did not expect this. I assumed that the highest epic settings (epic elite) would have everything dropping a blue coin. This is not the case.
On heroic normal, the weakest setting, sometimes nothing dropped.
My conclusion is that there are three efficient ways to farm blue coins in Zawabi's Revenge entrance corridor:
- Heroic hard/elite: bash through corridor, then stay towards end and kill the elementals as they respawn. Eventually, the efreeti will respawn but the gates will close. If you have DDoor, you could return to the entrance and kill through them all again.
- Heroic hard/elite: bash through corridor, kill everything, reset. This has the advantage that the one collectable resets for collectable farming.
- Epic normal: bash through corridor, kill mephits and efreeti; stop after killing last efreeti, reset.
It is noteworthy that resetting places you by the Desert Caravan quest entrance, so you must run back up the hill. If you are able to DDoor out, you can exit and be very close to Zawabi for faster resets and reentrances.
I did not encounter any champions at any point of my testing, so unfortunately there is no double farming here.
FYI obviously do not kill Lalait or you must reflag with ADQ.
In a short time I had easily 150 blue coins. This does not generate the superior purple coins, but it is fast.