Depends on your definition of reasonably priced I suppose. I got a replacement for my GS from my local dealer and with a bit of discount it was about 70 quid but my reasoning was that I wasn't taking a gamble with fit. As it was the cable had broken on mine so I did have to remove the unit. Remove the old cable, reassemble, feed in the cable as you turn off the radio, job done.
Other, cheaper solutions are available