What method do u think is best to get blacksmith to level 4 ?

Foxgodz - Heavens Tear

Currently i'm lvl 59 and have my blacksmith bar at lvl 3 filled up.However I have still to make three 2 star weapons and im contemplating the different ways of getting to level 4 to make my Twilight Temple weapon.As follows my thoughts.

method number 1:Buy the mats ingame and make all three 2 star weapons myself.
method number 2:Buy the weapons readily made to achieve lvl 4.
method number 3.Buy the mats using the cash shop and then make the weapons.

I know spending in cash shop to buy the mats is the easiest method,however what will be cheaper coin-wise?

Take in account the gold u spend on mats in the item mall can also be used to get coins.

What method do u think is best to get blacksmith to level 4 and why?