I'm 22, Just off my Ps, and my '99 GSi Teg cost me $450 p/a from Just Car for Third Party Fire and Theft. I found this reasonable, especially when compared to RACV's $750. I didn't go comprehensive, as I only paid $6k for it, and comp was about $1.6k p/a, or $1.1k if my excess was $2k. I figure I'll do some work to it over the next few years, and when I'm 25 I'll start comping it.

Congrats on your purchase! What a great first car.