Hmm not sure why you would want to... US machines on the whole are NTSC only (though they may output PAL 60). If you are buying new then just ensure that it is already multiregion to begin with. I doubt tbh there will be any savings buying from over there.. UK machines are very comptetively priced and so unless you were after a speciifc US make, buy it here or from europe.
Any reason ? Is it the upscaling to "near HD quality" thats interesting you..? I would look at one of the Denon's over here.. should be more than a match on the samsung... if you do import you will need a stepdown transformer.. and you will have to add duty and VAT to the price of the player + shipping.
Bought a Samsung DVD-HD841 about 18 months ago for $99 from Costco.Use it with a transformer I bought from ebay.The multiregioning was no problem,but initially it changed all my Pal discs to NTSC.Then I upgraded the firmware to HD745 then to HD950 with firmware I got from the ZoranDVD Yahoo group.Works really well with my Sharp GA3 TV,and hopefully will keep me going till I get HD.