Supra are the useful tools. If you are 4 star with them, then Lucis do not *really* help you. At least, not yet.

We do not know what the stat requirements are going to be for level 60 high end crafting. The only thing we really do know is that higher stats cannot hurt, and can only help. For all we know, Lucis is going to make the difference between easy leveling and hard leveling.

That said, Lucis are not that expensive to obtain, more time-consuming than anything else. Some prefer the Militia Choker (which makes sense, given the ingredient list), I have found that once the Raptor Sinew supply is gone(Hippogryf Leather being too easy to acquire), it is easier to simply gather the materials for Madman's Whispering Rod, of which you can gather the materials for 25 per game day if your Botany is level 50 with AF gear.