I believe 100% that Raiola is handling the business. Mario might have been saying he wants more salary but that's about it. Raiola is the businessman here. You don't seem to understand that players really don't care about the exact numbers involved in contracts (after they've talked with the agent that "I want more money"). Then it's up to the agent to deal with these issues. That's why they are there.
Balotelli is surely a greedy one, but I'm absolutely sure Raiola is the one stalling this deal at the moment. He wants to take that extra million I thinks is up for the grab there. Do you honestly think Raiola calls to Mario constantly asking "Hey, do you want 3,5m€ per season?" "Do you want 4m€ per season?" Do you want 4,5m€ per season?" ? They don't act like that. They've held their meeting before Mario left the States, and then it's Raiola's task to do the deal.