I think after 30,000 or 50,000 shots, to get a new DSLR, or pay to repair the shutter, is reasonable.
But the problem is:
You are on an important trip (business or family vacation), and the D50 dies silently, without giving you a screaming, before you set off ...
So is it a good plan to get a new one or replace the shutter beforehand? Or simply bring a stand-by DC during the trips which is near the expected end-of-life ???
Or are there symptoms e.g. strange shutter noise, to alert you?