Your opportunity cost point is more obvious to me than your Rita Skeeter point. Harry just sacrificed several lives, not just in people he could save today but almost certainly in people he could have saved once the war started. Potentially justified if Hermione is nigh-irreplaceable in the project of discovering the underlying structure of magic, which might give a hint as to where the plot’s going. But I’m not sure Harry could reasonably predict that.
Your opportunity cost point is more obvious to me than your Rita Skeeter point. Harry just sacrificed several lives, not just in people he could save today but almost certainly in people he could have saved once the war started. Potentially justified if Hermione is nigh-irreplaceable in the project of discovering the underlying structure of magic, which might give a hint as to where the plot’s going. But I’m not sure Harry could reasonably predict that.