I am thinking of a project that will include several similar units networked together. Each unit should have its own configuration. The Arduino itself should write the configuration data to the memory. That means that an external memory is required.
After a short googling I discovered the 24LC256. The capacity is enormously greater than my needs but ... what the heck ... it costs about 3 USD.
The fact that it will store the configuration means that I do not have to worry about the cycles of write (it is not a data logger).
I have only one concern. Would it be possible to address a specific area in the memory? It will not be convenient if I have to read/write large blocks in the RAM of the Arduino.