I just happen to still have the price sticker stuck to my addi 4 mm (US 6) circular needles case and it says Euro 5.65 = $ 7.60 at today's exchange rate. So it wouldn't be worth getting just one (due to the postage), but more than one would make sense! I can ask at my LYS if all their addis cost the same or whether there is a difference in price with the various sizes.
I have my eye on a few american things which I will post about when I have some "funny money"....hopefully soon in other words!
It's great to see that there is enough interest and that we have a place where we can announce when we're ready to do a trade!