General

For getting tiers, I prefer to use Red Cubes. I also use Red Cubes to get the initial good stats my classes require, then I switch over to Black Cubes to get fish for better stats. With my experience with the craftable cubes, they tend to not be as cost efficient in the longrun, if you're buying them from other players; however, one good thing about the craftable cubes is that they are somewhat cost efficient, if you're able to craft them yourself, as the ingredients and fairly easy to obtain and don't cost much. Other than that, craftable cubes don't really benefit you much, other than being a "free" way to obtain potential. The reason for this is not only the fact that have a low tier increase rate, but they also don't offer the bonus rewards that Red and Black Cubes offer, primarily the potential stamps.

The stamps themselves can help pay for extra cubes that you need, if you're able to offer it as a service to friends for financial compensation. This is my experience and knowledge on the cubing system; I hope this advice helps you decide on what to do.

It is cheaper to craft cubes, but crafted cubes have more "trash" lines and lower chances of tiering up. Honestly, I don't know which is better in terms of efficiency.

i get much better stats/tier up rate with black cubes than any other type of cube

well you can get all the ingrediates for crafting so basically it could be free.

If you're already a meister then it should be cheaper to make cubes.

I can't confirm anything since I'm not sure of prices of either in mesos atm

given the nx rate, probably cheaper to craft your own cubes