I also looked at VPI for my buns. I ended up not going with them though. I saw alot of really bad reviews about VPI. Unfortunately, there were very few reviews by bunny owners (can't remember now, but like 1 or 2?) .
There were also positive reviews, but the bad ones scared me away. You might want to check them for yourself and see what you are comfortable with.
What I do recall is that is was about $12/month/bun and you had to have had your rabbit for at least 60 days (or something like that).