I managed to buy Lumines Puzzle Fusion at my local Comet (Aintree,Liverpool) this morning for £4.99
The sticker on the box said 12.99 yet when i went to buy the game the reciept said Lumines was only £4.99!
This is ideal if you want to step down your PSP fimware to 1.5 for homebrew. (ULES00043)
I can't confirm if this deal is nationwide.