That's strange. This is what they state for International Shipping:
We are pleased to be able to ship items of upto 2kg of weight to anywhere in the world. Where we can, we will also send items that weight above 2kg. Please note that if you try to buy an item from outside the UK that weighs more than 2kg, then this may will be removed from your basket at checkout. It varies from country to country however we can deliver to most European destinations parcels that weigh upto 15kg!
http://www.gameseek.co.uk/c/delivery.php
Zelda:BotW has been available for £40 with the Amazon £50 discount and GameSeek has it currently for £45.00 which is currently the lowest price around. Very has the WiiU version of Zelda:BotW for £34.99 (C&C).