Overpriced and over here

Christmas has well and truly hit us like, well, a large pile of snow which has slid off the roof after having shut the door too hard (not the best metaphor in the world, but - dammit Jim - I'm a bookseller, not a writer). You get the idea. Crockatt & Powell (those punk rockers of the bookselling world) describe the feeling quite well. We had an issue this week involving a US book, and it's something that I can't for the life of me work out. If we buy a US book from a wholesaler, they treat the dollar value as pounds, which would cause no problems if a) the Internet wasn't around to compare prices, and b) the pound wasn't currently trading at close to $2, which makes "doing the math" (as our US friends might say) a snap. Customer comes in, brings a book to the desk, sees $40 on the book and thinks "must be approximately £20". Oh no, our system says £40. Our invoice from the wholesalers says we bought it for £40 (minus our discount). A phonecall to the wholesaler says "we charge the full UK currency equivalent to cover the costs of getting the book over from the US". What? But it's Dorling Kindersley. They're a UK publisher (well, they were). And the book was probably printed in China anyway. How did you bring the book over from the US? In a sponsored canoe, one at a time? (My bonhomie has become slightly dented during the conversation) The annoying thing is - there's no way to spot a US book before we order it (at least, not that I know of in my time-challenged, customer-needs-it-yesterday, work-environment) So - anyone out there like to enlighten me (a very ignorant bookseller) if there is an explanation about why this situation exists, and tips on how to handle it? THE used to have an American Bookshop (operated on their behalf by Paperbackshop.co.uk) but it closed recently as being non-viable. Perhaps there's a clue there...