https://rimmerbros.com/Item--i-CUH102340
This is the whole unit and at a price that IS expensive.
My drivers window did the same as yours, it was the cable that had rusted and snapped. There are window regulator kits available on EBay for about £10. Takes a couple of hours but they do work. Mine has been fine since. If Andy (Trikey) has one, it's a simpler job, but get your mechanic to smother grease on the cables, runners and cable ends in the white clips, as they are exposed to water/moisture inside the door.
https://www.ebay.co.uk/itm/263550774254
Link for regulator kit incase you or anyone else need it.
Lee.