Whilst I live in the UK I am visiting the US on holiday in December. I aim to purchase a new 15" rmbp and can see a big difference in the price between the UK & US. Should I buy when I visit? I'd also like a new Ipad Air. Will I be limited on what I can buy in the Apple shop in Washington DC? Will Applecare if purchased in the US cover me in the UK? Any advice will be appreciated. Imac 2013 27" i7 & Ipad 3.