If you have the 1e DMG, I'd probably go with those prices as a base (as Rhialto says above, they should probably vary based on how the temple views the players); so cure disease is 1000gp a pop, and cure critical wounds is 600 each. So assuming a temple you have neutral relations with, I'd estimate 3200gp total. Members of the church, assuming they're in good standing, could get 10% off, and of course it's a good opportunity to have the priest go "sure, I can cure you, but I have a job that needs doing..."