It's annoying how much cheaper US gets them, a lot of the time it feels like i'm getting a decent discount then see in America they can get it even cheaper. However from what i've experienced so far sets in the Uk sell for higher than in the US so although we pay more initially, we do get a greater return. There is also considerably higher competition. I'll use an example
Currently on Amazon, Hogwarts castle:
US - Lowest Listing $320/