There was a comment made about latent awakenings that I sort of just dismissed, but on second thought I think it deserves a bit more attention.
Latent awakenings have questionable value for their MP cost. The resists have the highest impact per latent, but that doesn’t really make them more MP-efficient. Unless you need a certain latent to reach a certain breakpoint, they just don’t have enough impact per latent to justify the MP cost.
MP is a scarce resource even for whales so unless you intend to drop a few packs every godfest you’re going to run out quickly if you don’t show some discretion. If you want latent tamas, just wait for them to appear as invades in dungeons and farm them there; this should be more stone-efficient for most players. Maybe you won’t satisfy your need for instant gratification, but in the long run it’s a better use of resources.
Why should you conserve your MP? For the MP Shop-only monsters. Even if you don’t like any of the monsters revealed so far, there will almost certainly be one in the future that would be a great fit for you. This is particularly true if you’re a collab junky like myself; I expect many more Claire-like offerings in the future. Don’t regret using your MP already when that day comes.
That being said, if you just what to pimp out your favorite monster or monsters, go for it.
Now, to answer the actual question that was asked: if you want latent awakenings, what are the best options?
You should still wait to farm them rather than buying them, though.
As for buying other things, just don’t be this guy: