Hi, I am shipping a 3 bedroom house worth of stuff in a 20ft sole container. Cost range from 3400 to 3600GBP, add on Oz quarantine cost etc, your averaging about 4000. The best quotes we got were with John Mason and PSS. Defiantly worth it as the total of our estimated shipping items is 36000. So it's best to get some insurance at 3% currently. We only insuring part of our shipment - the expensive items to replace to keep cost down!
Hope this helps!