The US and UK models are identical afaik. My pc3 usb was bought by a previous owner secondhand from US.
Assuming you are getting it posted to you, like anything else over about £18 (i think) you will get stung for tax when you import it so most of the savings will disappear.
This is what HMRC say:
2.2 Do I have to pay import duties and/or import VAT on goods sent to me?
Most goods arriving in the UK from outside the EU are liable to any or all of the following taxes:
customs duty
excise duty
import VAT
and must be paid whether:
you purchase the goods or receive them as a gift
the goods are new or used (including antiques)
the goods are for your private use or for re-sale
more of that on
http://customs.hmrc.gov.uk/channels...pertyType=document&id=HMCE_CL_000014#P21_1913
I'm not sure where you stand in terms of warranty either.
Rob