Brian,
You may want to consider joining the UWA outdoor club. They have a variety of windsurfing gear ranging from beginner rigs to wave gear. Membership is about $50/year and there might be a small nominal fee for using the gear (say a few $). Initially you will only be able to windsurfing with one of the club instructors to ensure you wont hurt yourself or the gear. For this reason access to the gear initally depends on the avalibilty of instructors but once the club is satisified you are not going to break thier gear...go for it. I learnt to windsurfing with the outdoor club and it is by far the cheapest way to get into windsurfing (and kayaking and rock climbing). see
www.outdoorclub.com.au/ for more info.
Cheers
Brett