The vaccine is available for women up to 27 years of age. However, you need to get the whole three doses (spread over 6 months) before you turn 27. So you will need to be 26 1/2 at the latest before they will give you the vaccine.
If you are outside the age bracket, you can get the vaccine for about $460- for the three doses.
I would be interested to hear what any long term effects could be with this vaccine. The free course is only up to the end of 2009 I think so if I want to get mine then I'd better not waste time. Got to wait until after pregnancy (turn 26 few days before due date) then I might give it a few months and get mine done.