Replacement Rear Door Locks

[Invictagunner]

The rear door locks on my 2002 Passat Estate have started to stick and occasionally not unlock when the central locking system is activated either by the remote or the internal drivers door button. Both sides can be affected but the faults seem to occur independently. So far it has always been possible to open the door from the inside. The locking cycle has been 100% reliable so far. My local independent VW guy thinks it is probably the lock PCB / micro switches that are starting to fail. CCM is dry and no other potential CCM related faults showing.

Firstly, any views on the diagnosis?

Secondly, any views / experience of fitting after market replacement locks costing £25 on Ebay versus VW price of £125. The independent guy is happy to fit either but has no real experience of the potential life of the much cheaper replacements. Supposedly they do have a 12 month warranty but this means very little when the labour cost is significantly more. Any experience of after market locks, good or bad gratefully received.

Thanks

[caldirun]

I have fitted recycled locks from pre 2005 cars as the 2005 locks are really bad, slightly tricky job.
The other possibilities are the mech needs cleaning, the A post plug and sockets are corroding, the wiring has cracked (very unlikely on rear doors)