Hiya!
Yep, although the price variances on the 'exact same' model nowadays are less than they used to be, the US priced version is still substantially cheaper than the UK version. Laptops used to have quite a difference - sometimes hundreds of pounds cheaper in the US, but much less so nowadays - other electronics will still have substantial pricing variances in the US Dollar favour.
Reason is the USA is the biggest market in the world for all consumer goods and therefore enjoys the best pricing. The UK falls down quite a way in pricing stakes and also has less choice generally. You can thank the UK's trading laws and red tape for running businesses here for that - many exporters quite often skip the UK as a market altogether ! those who do export (to) here, also put on 'UK pricing' for the goods - which in simple terms means 'it's more expensive here' when it hits 'consumer level'
As for buying 'personal' level electronics, you'll have zero problems at customs provided of course they're out of the original wrapping/boxes. Laptops, Digital Cameras Still/Video, MP3 players, Watches, mobile phones etc etc will NOT be subject to customs and/or Import tax charges - all you say is they're personal items. Of course, don't bring over like 4 of each !
The only caveat is of course warranty issues - those companies who offer a worldwide warranty may still have clauses which say only applicable to persue in the home country/market it was bought in/meant for. Others will say let you take the item to an 'approved' or the company's stores/channels here in the UK regardless of where it was bought.
For me, I've been buying up electronics in the USA and using them here for years and years and currently not needed warranty claims. My personal view is, for the substantial amount of money I've saved in purchasing the item, if it goes wrong, I'm willing to stump up the repair cost if needed here - of course your own personal view may be different.
As ever with electronics, do as much research as you can into particular models of gadgets you may want to bring over - 'most' things should work/operate just fine here especially 'personal electronic' items etc - and you should be good. Video cameras is one area to be careful of, The USA uses NTSC coding and the UK uses PAL, and although theres many UK DVD players, media centres and the like which can play a NTSC signal you'll still need to be careful as to if/which models you have actually have that capability.
For in depth stuff on HD video recording and potential playback issues and limitations, pop over to
www.avforums.com where you'll find some serious techies with the answers to pretty much everything!
Cheers!
DtM! West London & Slough UK!