For a low hours pilot on a Standard Cirrus worth say, £10000, you are likely to be looking at a premium of around £700 to £1000 if you are including the hull value. It is likely to have a £500 excess. Expect a loading of around 10% if anyone who will be flying the glider has made a claim. Having 50 hours+ brings the insurance cost down, so consider staying on club gliders until then. Having your Bronze C is even better.
The cost of hull value cover is very closely related to what you value the glider at.
It is worth shopping around, and if you have any hours (even P2) on light aircraft, hang gliders or paragliders, it is worth mentioning them, as some insurers will take these in to account.
If there are other members in your club who you would be happy to fly your glider, particularly if they are more experienced, consider offering insurance shares. You retain ownership of the glider and they have an alternative to the club gliders. Make sure anyone you consider is aware of, and able to pay, the excess in the event of a claim.
It is worth checking what else is included. My policy covers the trailer, parachute, radio, rigging aids and driving my car airside. The latter can be very expensive to buy separately, so well worth having.
Mechta (who has just reinsured his glider)