Speaking as an Australian where the vaccine is free to young girls and was fully funded for the up to 25 year olds...
There was some commentary from the Australian scientist whose work led to Gardisil that because there is wide coverage of the vaccine which should cover 70% of the potential cancers.
Then the arguement was that the cancers are generally slow growing, and if abnormal 'pre-cancerous' cells are treated surgically then the woman is at a greater risk of pregnancy issues, c-sections, preemie birth etc.
Not so much a cost saving measure but instead trying to save those preemie births etc IF the pre-cancerous treatment was not necessary
Well if a woman develops pre-cancerous cells at the age of 18 and doesn't have a pap until 21, she better hope that its really really slow growing.