Apple changed some prices just now (not in the UK though)
https://www.macrumors.com/2018/01/25/apple-tax-pricing-changes-foreign-app-stores/
[doublepost=1516904152][/doublepost]Looking at usa prices, a top end Macbook Pro (not that I would buy one the way they are now) is GBP £2,700, and a USA one is USD $2,800. Converting the prices gives us GBP £2,700 = USD $3850 at the moment, which seems a lot, over USD $1000 difference, but a couple of things mean this isn't a true comparison.
Stripping out UK VAT, that puts the UK one at 2,700 / 1.20 = £2,250. Convert to USD = roughly $3,200. That's a roughly 15% difference in base prices, USD $2,800 in the USA and USD $3,200 in the UK. Call it the cost of having a viable education & health system (ba-dum) free at the point of use.
Next factor, lots of British people forget that USA buyers almost always have to pay various unlisted sales taxes on top (seriously guys, why are USA shops incapable of putting local taxes on their shelf display prices, it's not like a brick shop randomly moves around overnight). So let's add, at a guess 10% sales tax to the USA price. $2,800 x 1.10 = $3,080. That's roughly a 22% difference to the UK equivalent price of $3850.
For the $800 difference, it's true, you could almost fly to NYC, and clear a profit after buying a Macbook Pro inc sales tax. Just like in the good old days. That is, if you were able to somehow avoid the UK import duty that you should be declaring (many don't). For anything cheaper than a top-end 15" Macbook Pro, it isn't worth it.