It's going like hot cakes, is it!
The reason you see double the price on Play, Amazon, etc. is because the Company itself is out of stock (who sell at RRP), but people selling them through their own account (much like ebay) are not regulated in how much they charge.
So, say I bought the game, left it in it's wrapper and went and sold it throuh play.com, I cold charge whatever I liked.
I managed to get one through ebay for �20 plus �6.99 p&p from an Ebay store based in Hong Kong. It arrived today and it's perfect and exactly what they said it was (i.e British version). Would you like a link to the seller?