The old 80GB PS3 is down to £244.69 at Argos now. It says there is limited stock because it has been discontinued, but my local Argos (King's Lynn) has 5 in stock. Also, it IS in stock for home delivery.
You can combine this with one of the PS3 deals, personally I would take the free game and select infamous (which they are otherwise charging £43.99 for!).
Also, you can get £20 of Argos vouchers for spending over £100. The £20 voucher offer finishes today (Sunday), but some stores stay open until 5. Additionally, you could always order it online. Online you will have to pay £5.80 for delivery, but this is almost absorbed by the 1.5% quidco cashback.