I feel I should clarify this a bit further. If you want multiple characters that is fine, but just know that in order to play whatever job you choose to play correctly, you MUST level at least 2 other classes to 34 on each character. For example Black Mage pulls abilities from Arcanist and Archer. So to play my Black Mage correctly, I must also level an archer to 34 and an Arcanist to 34.

This means it becomes instantly more cost effective to get more and more max level classes on ONE character, since if I say choose to go Bard at some point in the future, I have already done over half the work of leveling him. Chances are, if you want to level 3 jobs to the max, it is going to REQUIRE you to have achieved at LEAST 34 on every single class in the game. Combine that, with the xp boost you get on subsequent classes and sticking to one character instantly becomes a better choice.

If you are doing multiple characters for looks, it will save you time, energy, effort, and pain by just buying a bottle of fantasia (when they start selling them directly) and then completely changing your look.