Hey Lads !

Here we go there is finally a Refine Rebate Event going on and I really need some Advice.
First I would like to point out that I´am playing on a very restricted Budget. I get the 50 Coupons Monthly Card, but thats about it. I don´t spend more on this Game.
I got a Question about my POS1 Ninja and the Refines.

My POS1 has following Refine Levels: Headgear Lv.8
Weapon Lv.8
Scroll Lv. 8
Chest + Necklace Lv.7

What do I focus on? I got 0 wish Credits on everything. Should I up the Chest and the Necklace or should I focus on the Headgear? I got 80 Advanced Refine Runes so not enough to Level Up any on the Lv.8 since they take alomst 500 Attempts. I still need to know what I should focus on over Time.
I was thinking of the Chest tbh to boost the +94% Iniative Bonus I got on the Chest Purify.
I´am Level 81 and my POS1 got about 7,1k Iniative.
But I´am very unsure. I hope you can help me out Lads! Thank you<3