Ebay Global shipping (I believe is shipped twice), in this case shipped once with in a US to a US Hub, then processed with adding the Importing documentation the shipped again to the customer in the UK.
An example of an order I've did a few months back:
Price | US $38.70 |
Postage | US $16.07 |
Import charges | US $15.36 |
| US $70.13 |
I'm pretty sure it is also VAT on both price and postage cost
And as Rui says it looks like there is a clearance/handling fee
But can still work out cheaper than getting VAT bills and handling fees on this side.
In my case to make it worth while I bought 3 items from the same seller, but it's gonna vary between sellers and how much they charge on postage for extra items, ect.
EDIT: you may even be able to work out the clearance/handling fee by temporarily increasing the amount of items (before purchase) and some math fun