While hunting for iron grass with my mage, I was using mana arrow lv. 1, which costs 50 MP, and I was able to OHKO monsters (clam shell, iirc?). So my MP was regening all the time, since I wasn't hitted. THEN I thought that Aura would really come in handy. But later on, mobs starts to turn aggro, so I have to agree with Recette. For light mages, maybe you can, or even should get it at 1st job. But just GET, not level more than lv. 1. It's still a pre-req for Hearts grace and STILL - it IS usefull, not comparing to mist or dark barrier/SoH, but it is.
The greatest XXIst century scammer!