Importing via sea can be a whole different ballgame to air.

What your probably looking for is Less than Container Load, LCL, your in a shared container so there is unloading and clearance charges this end, UK, in addition to VAT, duty and the actual shipping charge.

Have a google and a read of some of the business forums and talk to a couple of UK shipping/logistics agents, cost varies wildy, couple of calls is always worthwhile.

Cheers
Adam