I found healing auras to be handy for topping off HP while exploring, etc (though if I hadn't stopped distributing attribute points after level 15, my natural healing rate could have been faster). I mostly relied on random levels on loot, but when replacing a belt with the only healing aura I had at the time, I added level 10 to the replacement; IIRC I tried it without the healing aura for a while, decided to add it, then not long after found a better belt.
I got a level 10 healing aura on level 24, after taking over the battle tower (after entering the Master's chambers, picking up the 'Note from Maxos' completed a quest, and one of the optional rewards was a bracelet with a level 10 Healing Aura).
I bought a few pieces of equipment to get the enchantment formula, as well, selling them after removing it.
