It's £99 fitted because of the watchdog program about them. Theyy're very easy to replace and dont need programming, yo will lose your mileage though.

Do a guage sweep test (Ignition off, press in the mileage reset button, ignition on pos 2, release button when "TEST" is displayed, press button once more) and see if the guages are working correctly.

But yeah, very common fault!