Hi Gareth. I had a look on eBay , and I wouldn't say them mad crazy expensive... One I had a look, was something 40 GBP delivered...
Wouldn't considering use second hand door lock, as it probably won't last long... Sometimes could be lucky... But by my experience... Not .. had Passat before, couple times changed door locks with used ones, didn't las more than couple months... (Typical problem with microswitches).. tried fix myself... But never worked out right... After bought brand new locks, problems were solved..
Car just passed test (MOT), just didn't lock the car , left it unlocked , tester didn't notice that lock won't unlock , but still I'd love to get it fixed, as some times very inconvenient get open door from inside , driver side, once door is opened, if not locked, door lock operates normal .