Nobody thinks that, maybe the the exception of t4 stuff.
The difference in maintenance is just a canyon wide. That's all.
But the changes to evasion and aoes and the like, and the change to defense, might start changing this drastic imbalance.
Edit: The critical disparity presently is that melee need a lot of upkeep across tiers of content which mages generally do not. If you have melee, you need a healer to watch them and you probably need a geo to protect them (and/or perhaps a bard--scherzo or summoner).
Mages also all generally love the same buffs as the guy providing them.