I'm surprised how close minded everyone appears to be on this subject. I'm with the OP, I love the idea of POSSIBLY being able to meld lower level materia into higher level. There should be a similar risk-reward scheme as there is with forbidden materia; there is a chance of success, but it is not guaranteed. The more/stronger materia you attempt to meld together, the higher chance of failure. This would give us a use for the 20-30 MIND I/II's we all have laying around.. WTF SE??

Anyways, I would appreciate if anyone opposed to this could state a logical reason why this is a bad idea. There could even be an NPC that does this for a fee, adding to the system's value that of a gil sink as well.