The Netto flyer for January 5th lists a Motorola phone that looks like a W156 for £9.99. It doesn't say if this is sim-free, or if it comes with a sim, or any call credit. This phone has been on sale for ~ £15-£18 before now.
It looks to be an updated version of the F3, with a high contrast LCD display, and with higher resolution so you can read more of a text message. I have an F3 and it is fine as a phone - good reception, call quality, a loud speakerphone, long battery life, robust construction. The screen on the W156 should be better for text messages.
There is a limit of one per customer.