Also if you level crafters - you can meld your own gear for free, so all you might be out is a materia or two when they go smash as you try to retrieve it. Leveling crafters also means you can save yourself repair bills and repair even in the middle of a raid or dungeon as long as you carry around a stack of the right grade dark matter - which you can get from GC seals, so no need to spend money there at all.

To OP, I wouldn't bother OVERMELDING unless you are going to do savage or ultimate, but melding the normal slots would never hurt.