Quotes aren't too heavily biased by the container size, it's the packing / unpacking time that's the issue. So if you've lots of small fragile things that need lots of wrapping then it will be more than someone with a few large items. Also, the road transport in the UK and NZ, the need to double handle if they can't get the container to the house will add more. Actually, after a few losses then I really think I'd prefer to get 2x20' containers sealed at the house rather than the 40' and shuttled via smaller vans.