Cheapest I've ever seen it, even less than preowned.
I noticed this in HMV about a week ago, labelled at sale price of £6, quite a few left. Went in today to get one and they were no longer out on display as they have taken away a lot of sale stock/old stock and just put them out the back. I'm guessing they were getting rid of this one as the Move Edition is now standard.
Anyway, there's no need to pay for the Move Edition if you can get this as the upgrade to the Move Edition from the original is free on the PSN store.
If they don't have it on display in your local HMV, ask them to check stock for you!