More ways of increasing Extraordinary Ability DCs?

[Yahsei]

I have a Gulch Gunner Gunslinger who just got the powder burns archetype at level 3.

Paizo PRD wrote:

Powder Burns (Ex): At 3rd level, the gulch gunner learns to maximize the damage dealt by a firearm at extremely close range. When the gulch gunner successfully hits an adjacent foe with a ranged firearm attack, she may spend 1 grit point to deal an additional 1d6 points of fire damage from the muzzle flash of her weapon. The target must also make a Reflex save (DC 10 + 1/2 the gulch gunner's level + the gulch gunner's Wisdom modifier) or catch on fire. This deed replaces the pistol whip deed.

With the archetype, I'm getting grit points every turn and I am using it on this. My save DC is 14 (10+1 Level+3 Wis Mod). I'm too wrapped up in Gunslinger Feat taxes to get Ability Focus right now, but I want to increase the DC. Is there an item or trait I can retrain to increase the DC?

[Mysterious Stranger]

Increase your WIS is probably the best way. A headband of WIS +2 costs 4,000 GP.

[Yahsei]

Mysterious Stranger wrote:

Increase your WIS is probably the best way. A headband of WIS +2 costs 4,000 GP.

Ah yeah, I'm going to get one after I get a Revolver.

I was hoping for a cheaper item or trait that focused on abilities. It'll go up to 15 next level anyways.