Just been to Asda Milton Keynes & saw this Omron blood pressure monitor for £10 down from £20. An excellent price for this as normally its £15+ everywhere else. It also has the medium size cuff included with it.
Don't know if this is nationwide, but Asda Milton Keynes had plenty available.
Fully automatic blood pressure monitor
Large easy-to-read display
Intellisense technology for quick, comfortable and accurate measurement
One-button operation: simple, quick and easy to use