What's better? The birth control pill or an IUD?

that fact that the mirena (which is an IUC) is more effective than birth control pills, you dont have to remember to take the pills and it is cheaper when you add it all up....mirena costs around 530.00 for 5 years!!! you spend at least 1,200.00 a year on birth control, and most insurance companies cover it, or most of it. and since its not metal like IUD's (its plastic) it has less side effects. i think that and IUC would be better..