Anyone knows exactly which weapons can be obtained with lucky coins?

[Hrith]

I usually use Launcher over Needle, because the former has over twice the ATP of the latter. So even if you hit one or two less targets, Needle still fails -- not to mention range.
Launchers are rather bad if you're not in a team of three or four, though, and nothing beats Needles for soloing, amazing crowd control weapon. But for dealing damage, hmm, just no.
Launchers also have amazing capacities: they don't need to lock to hit, they hit flying things with much more ease than other weapon types, they hit several parts of bosses and some monsters (Girtablulu) with very low chances of missing (shots and needles really fail at Dal Ra Lie, Barba Ray, Gol Dragon, Gal Gryphon and Girtablulu when they are moving).

S-Rank Needle: 150 ATP
S-Rank Shot: 260 ATP
S-Rank Slicer/J-Cutter: 290/310 ATP (twice Needle's)
S-Rank Launcher: 370 ATP

It's easy to see which weapon fails.

I do use Needles, that's for sure, but it's for spamming the special, nothing else.

And any 5-star weapon (or less) completely fails, period.


Edit:
I still think Slicer is the best weapon type in the game by far.