Welcome to BB
Have you checked with your PHI as to how long the waiting period is for IVF? Our health insurer originally was a 24 month waiting period, but changed it to 12 months just before we found out we would have to go the IVF path. Might be worth finding out (if you haven't already)

Will paying the extra premium give you any extra benefits that you will use after IVF as well?

Have to duck off, sorry for the short reply..

Nic