Quote Originally Posted by Snugglebutt View Post
Some things can be capped on all stats for that item, those it is worth doing.
A quick amendment to this: Some things can be capped on all stats for that item without overmelding Tier V materia, those it is worth doing. All of the accessories, for example, require at least one Tier V overmeld to be completely capped. The value in doing so is decidedly questionable.

Tier V's - even Gathering Tier V's - are still expensive enough that attempting to overmeld them will likely be expensive enough to outweigh any possible profit you might make with them beyond what you could make with just Tier IV overmelds. The amount of gil you spend (or, if you spiritbond your own Tier V's, the amount of potential gil you COULD have made by selling them instead of melding them) will not be paid off until well after the next tier of equipment is available. At which point you'll be starting the whole melding process over again.