How many Shutter Clicks on a New Camera considered normal?
I purchased a quotes new Nikon D750 and checked the shutter count and it has 264 Shutter Clik count on it.
Is that suspect of a returned purchase or used camera?
When you buy a new car, what is the minimum number of miles as shown on the odometer that allows you to classify it as "new"?
Same for a camera. In my 75 + years of camera ownership, I have never had a camera fail due to shutter malfunction. I know this happens, once each major city sported a camera repair shop or three. Where are these shops in your city? I will bet none exist. That's a good omen and it tells me that cameras are very reliable.
I've never bought a new Nikon DSLR so I have no experience with them.
I have bought a few new Canon DSLRs. They have had anywhere from 0 to 16 shutter actuations when I got them, with most being at 0. Based on articles I've read, all Canon bodies are calibrated at the factory during the manufacturing process, so presumably the shutter count is reset at some point in the factory. Some, but not all, cameras go through a random quality control check at the end of the manufacturing process before leaving the factory. I've always assumed that is where the shutter actuations above '0' came from on my new Canon bodies. None of them appeared to have been unpacked and repacked when I first got them.