Bought one of these from Asda Grimsby today for gaming on (Steam) PC. I have a feeling this could be a national deal, so it's worth checking your local store. Seems a good price for an official controller.
• Play in comfort - A compact, ergonomic shape lets you play comfortably for hours on your PC or Xbox 360
• Vibration feedback gives you a riveting gaming experience
• Precise thumb sticks, two pressure-point triggers and an 8-way directional pad help you stay in control
• Flexible 9ft/2.7m cable length: The thin, flexible cord was designed to provide the sensation of wireless with all the performance of a wire
• Connectivity: Powered USB port
• Platform: Windows 10, 8, 7, XP, 2000, 98