$14.99(US) for SSL Certificates at Go Daddy
Cheap isnt necessarily good in security but there's enough large companies using Go Daddy certificates for them to be fairly stable with decent encryption.
If your needing something cheap and cheerful they have a sale plus increased cashback on the standard SSL cert. Its something that would be fine for low level processes. Add to that the exchange rate and even the deluxe certificates at $89 is miles better than the Australian prices I can find.