I spend around 200K pero on Kurito per month.
On guard events I spend 250-500K on half hp potions.
Rest I spend on N-keys. 1x N-Key + 1x N-Gacha cost 1500 Pero..

I hope they sell 5x N-Gacha + 1x Card Reveal for 9K pero again some day. I am down to my last 150 card reveal atm.