@Rapier, Gandalf only able to pay for neutral cards seems counter intuitive. Like lleimmoen was saying, his story is that he appears wherever he is needed with the support of his wizard abilities, whether he is supporting humans, elves, or dwarfs (he is not sphere"ist"). Limiting him to paying for only neutral cards is the exact opposite of why FFG made his ally version a neutral card that can be played with under any sphere. That is my objective analysis.
My subjective analysis is that to make a hero Gandalf only able to pay for neutral cards is silly. I personally never have more than 10% neutral cards in any of my decks, making Gandalf's resources essentially useless. And if you did have at least a third of your deck neutral cards, your other sphere's main focus will be on allies since there are a lack of neutral ones. Deck building is the acme of skill in this game, but limiting your flexability in deck building by using a duo neutral/sphere is poor strategizing.