With sea-freight shipping you need to be very careful. If you get a quote to ship, say, a 2 cubic metre crate from the US to UK, from a US shipper, they will likely quote the cost of getting it into a container and the actual shipping. This is relatively cheap. What they will not tell you is what happens when you receive the "notice of arrival" in the UK.
This will come with an itemised bill for approx 10 different charges, such as Customs Clearance, Duty Deferment, Port Security Levy (!) etc etc, many of which you will not understand. Some of these charges will be high because the agent will know you are not accustomed to importing and will double or triple the charge.
The total cost of all these charges will be higher than the original shipping cost.
As Fozzy mentioned, you get hit because most of these charges are the same for a crate as one full container.
I would agree with the costs Fozzy mentioned, as totals. It might be possible to save some of the cost by driving to the port at the right time rather than getting them to deliver it but the chances of a wasted journey are high as goods can mysteriously get lost for a couple of days or delayed for some reason. If they have to store stuff they will charge storage fees so you cant win.
Andy