I've done the harvesting quite a bit myself and it really does average out to roughly 1 stack an hour. Some days you can do it faster and others will be slower. With HELM gear, I'd manage about 1 stack for 3 sickles lost. Never tried without HELM. I liked doing it on BST/DNC with Lulush and Glyph Axe. When I'd get Chigoes on me, it was simple to kill them with Pet Attack>Whirl Claws. If at 300% TP on Pet, she'd some times 1 shot them. In fact it was sometimes faster to pull the chigoes standing on a harvesting node and do this. Just be warned that just like in Abyssea, using the node while your pet is engaged will disengage it. Would pull random treants/goblins to build my own TP if I ever had to heal.

It's also not bad for some other items. One of the harvested items vendors for about 10k a stack and one other goes for about 10k a stack on AH (Vegetable seeds if I remember correctly).

Ziz meat is another thing that's almost never on AH. Sells cheaper, but just as fast (maybe faster). It's an easy camp and using Yuly gets about 1 stack about every hour. With cooking, you can probably convert to Bloodclaw's for increased profit. Just do the math before making them as server prices vary.