I bought my dress in the US because it was so much cheaper! In fact I bought everything for my wedding in the US and left a lot of it with my parents to bring with them when they came over for the wedding because I had so much luggage of my own, what with moving and all.
I bought a Maggie Sottero dress which if I had purchased it in the UK, would have cost me almost twice as much
It was a bit of a pain to carry-on but well worth it.
I ordered a veil from
http://www.veilshop.com/ which I customised and it ended up being significantly less (about $80) than the veils I'd seen here in England, most of which were well over £100. I also ordered a hair piece from them and my jewelry from
http://www.1928.com/.
Everything I shopped for for my wedding was significantly cheaper in the US and since I now live in a fairly small town in Northwest England, I also had a much better selection in the US.
Good luck!!