To be fair to the seller, you got hit with their Europe-wide rate and I notice that other sellers of similar items charge even higher rates for similar items. In fact, many don’t even allow shipping outside the UK, too many scammers, same goes for the US version of Amazon Marketplace.

The folks you bought from actually offer free UK shipping for that item and, from the perspective of a user here, postage rates for Marketplace items are always listed very clearly, right above the “Add to Shopping Basket” button, right next to the price BUT, of course, it would be a lot handier if Amazon could recognise that the country you are in and list the relevant postage fee instead, rather than forcing you into the check out process to find that info.