The lifetime risk of ever getting cervical cancer is about 1%. So, $30,000 per prevention if you just count the girls, or $60k if you vaccinate the boys as well.
A policy simply doing -some- good is not sufficient justification given a finite amount of resources to implement it. You need to compare policies against the alternative uses of the resources.
Neither is the fact that "lives will be saved" a sufficient justification. You need to compare that against the lives saved with the alternative policy options available with the given resources.
Up to the voters I guess.