The cost effective way to reach 1600 TMA?

It seems 1600 TMA is the golden standard for a level 200 mage.
It enables bishops to 1 hit dark wyverns in the cave (80k HP) without charging big bang.

A level 200 LUK-less mage will have 1018 base INT.
So it's 1119 INT with mw20.

Before echo, the target TMA is 1600 / 1.04 = 1539.
Minus 20 MA from wizard elixir, 1539 - 20 = 1519.

The question is, how to distribute 1519 - 1119 = 400 TMA to gears so the total cost is minimal?
Is it worth to spend 1700+ coins (average success) to get mw30? (for the extra 31 INT)

 

I assumed with echo and wizard elixir.
Feel free to post your analysis under other assumptions.