@Paul > For the small amount you would save in the short run, it could cost you a lot more in the long run.
Firstly, I don't believe Pioneer USA would ship to the UK - given the cost of shipping and insurance (and possible customs) I don't think it'd be worth your while.
Secondly, if there did happen to be something wrong with the refurbished unit (unlikely but such things do happen) you would have to incur the costs of shipping the unit back to the USA (to California no less).
Finally, you've voltage considerations to take into account. USA is 110v, UK is 220v - so you'd need to purchase some transformers.
Again, I don't think it's worth it.