Not implying anything here but there are many factors. ;)
Licence cancellations, xpca priors, previous claims, place of residence, garage or street parking, age of drivers and if policy is nominated drivers only, windscreen option, hire car option, agreed or market etc.
I'm paying around $600 per annum with CGU. That is for market value, nominated drivers, no frills policy so not really a good deal at all.
Ring around and see if they are being unreasonable.

