I paid £390 for the iPad itself (including US sales tax of 6%) and the Bundlebox fee. This is about equivalent to the anticipated UK price of £399 for the 16GB Wifi iPad. Then I paid £120 for the VAT (a necessary evil, alas) and 2-3 day delivery. With slightly slower delivery, it'd have been £100.
So it was £500-520 in total. This seems reasonable considering I have an iPad almost two months early - gives me a nice head start on some things.