In Dulak I did all boats and a huge building and got about 4 gems. I mad 1.8k plat in about an hour. Im kind of looking for something better than that.
*shrug* My monk went there and made just short of 7.5k killing the entire zone.
You could try Acrylia but not knowing your gear or comfort level, I don't know if it would be good for you or not. My 73 warrior with her merc did fine but she didn't go into the castle.
I honestly don't know how I got results that were so much different than yours. Kill rate probably (I was 2-shotting much of the trash mobs and I killed every mob I saw, no skipping) but even that doesn't explain a fivefold difference.