I read that the D4 has like a 400,000 shutter actuation warranty.
I wouldn't pay any full price for 248,000 shutter activations. It's like a ten year old car, things happen.
A lot less than $5000 will buy various other new models, which can be quite fine cameras. Think about that a bit more.
The 400,000 number is NOT a warranty. The warranty is one year on the camera, period (and only for original owner).
But the D3/D4 do have better/faster shutters that have been tested, so it is just a prediction for a greater number until shutter failure.
Here is a database of when actual shutters failed. I do not know the source, or the integrity. Probably one repair shop? But the idea is some always fail early, some last forever, and there is a zone of probable failure rate.
Camera Shutter Life Database
D4 is not there yet, but the D3 shows most failures between 50,000 and 500,000. And a few at 5000.
Says the average D3 shutter failed at 218,000
(average of those in this shop with some failure).
Average for lesser models is much lower.
Seems fair to say that none of those old ones with no problems, and the shutter still working fine, were included in this survey.
Again, I have no idea of the accuracy of the data? But the idea is right.