What INT gear could I upgrade for the next 10-20 extra INT?

Idk how much "with the community" you are, but the best thing to do really is just borrow. I got 8x on my old set [it's higher now with new stuff, but haven't leveled in a couple months] but when I borrowed, it went 14x+

Make friends and stuff, it'll be a lot lot cheaper for you.

^ *seconds that* lol

Um, why not try scrolling the helm if you have regularly access to zak runs? You could easily obtain +10 int from scrolling the helm. Maybe look into upgrading your eye accessory too. I think compared with a shield, you'd get more int for your mesos by upgrading a few int more on eye. The wand should be easily upgradeable (even 12 int wooden wands aren't that expensive).