Check out e-bay! If you pick any "Buy It Now" item, you will not only find wild price variations, but the lower prices often disguise exaggerated postage and packing charges!
When the seller/shipper is not in the UK, and Hong Kong is the favourite for this trick, it's deliberate, it reduces the value that has to be declared on the customs declaration, which often means it gets in without any duty, but if they sold it for a more realistic price with lower shipping and handling, then it attracts duty.
Cute trick.
