Focusing on just essences, especially for dps jobs, is not looking at the whole picture. There is skirmisher, I think, but not any other cheap essences that directly boost their dps. Pretty stupid design to give only healers and tanks multiple choices.

On the other hand you can bring raise feathers to raise your healers and rdm, that damage skill that paires nicely with essence of the beast, cure 4 for the times you're missing a healer, debuffs for the boss, banners or party buffs. Imo, it's enough if you just bring something useful.