Door lock modules

[black light]

So I have just inherited a b5.5 Passat (great!)

One issue I want to fix is with the doors, I think I need some new door lock modules but can anyone confirm this is the fault? And a good source for a cheap replacement part (don't fancy spending 100+ on a genuine one)

The osr door just seems to be permanently locked.

To unlock any doors I need to press the button twice (or key in the door twice). The drivers door lock doesn't do anything unless using the key manually. There seems to be no errors on VCDS relating to the central convenience unit.

Thanks