PantherLotus
Professional Schmuck
It's a difficult one. I don't think you should be spending lapis on tms if you're f2p unless you really need them right now (for example if you just pulled your first zidane and have no innate dual wielders).
At the same time panther is right. Is there any point in saving a bunch of lapis only to blow it all on a 1.5% chance of getting the banner unit.
good point, but if we're being honest, the VERY BEST TIME to farm TMs is when you don't need them, because the converse is having a unit you can't use because you don't have the TMs!