I have seen it being sold for as low as £12.99!

Again, this is for US purchasers who can't get the great UK deals.

Also, I just received my copy in the mail today. Considering I ordered it Tuesday afternoon, it took 4 days to get here if he shipped it on Wednesday. Since the whole website/store is run by one guy, I'm betting he shipped it on Thursday since I do know he was overloaded by Killzone 2 (which is also $45 for PAL version) and LBP orders.

the box-art owns

here in UK, on Amazon you can get so many games for cheap prices.

yeah LBP was always dirt cheap in the UK.

I know that, I bought my game from there as well

I ordered the PAL version of the game because the cheapest I could find the US version for was $35 used. We shall see.

I'm just bumping this because I bought the game, beat it, and the deal is still going. I still have plenty to unlock in terms of prize bubbles and trophies.

Europeans in most cases have no problem buying stuff from US shop.  Should work the other way too.

I'm yet to try, but doesn't my credit card address have to match my PSN "home" address?

I did find some online virtual credit cards (mastercard based) that I can deposit funds from anywhere in the world, and it will act like a CC from UK. I don't know if I trust them though.