How much would a plane ticket cost to Arizona from Indiana in like a week and a half to 2 weeks?

Okay so school ends june 6th. I'm supposed to go to arizona really soon after schools ends. But, my grandpa hasnt gotten the tickets yet and hes out of town until sunday. How much do you think it would cost to fly from indianapolis to phoenix on june 7 or 8? I can do layovers too. Help!