Negotiating Funding Etiquette

[theatrehippie]

I currently have three offers that I am considering, with varying levels of financial support. School A (which is my top choice of the schools that I have heard from) has offered me $11,000 tuition/semester, which is great, but leaves me responsible for approximately $16,000 tuition per year. School B has offered me a 22.5% tuition fellowship (tuition is approximately $20,000/year), and I am under consideration for other awards (not sure when I will hear about those). School C has not offered me anything formally, but said they would "be on the lookout" for fellowships for me. They also gave me a credit waiver (not really worth much).

Should I let Schools B and C know about the funding I've been offered at School A, or should I wait for the complete funding packages from them first? Or, should I wait until I have heard from schools D, E, and F? Also, since School A is my current best option, if B or C increases my funding, is it gauche to ask them to increase in turn (since though they have given me the most money, they still manage to be the most expensive option)?