Getting better int items

Hello,

As there is a possibility of Neo Tokyo coming out, I've been told that the monsters much stronger than usual and I should consider adding increasing my mana pool for more HP.

I was wondering what is the cheapest way for me to add more int. Here are the items I already have:

15 int zhelm
6 int earring
13 int cape
5 int weapon
5 int deputy star
10 int robe
1 int broken glasses

My budget is 20-30mil, I hope this is enough

 

My base MP 1640, which is also very close to my minimum max mana. I'm currently doing 1 ap reset per level and my current hp is 3835. At that rate I'll probably reach around 6.4k hp by level 170. This probably isn't enough but I'll just have to do more research