As can be witnessed easily, many FP3 owners who recently replaced their camera and/or top modules with camera+ and/or a top+ modules are offering their former “old” modules for free or little money in this forum’s unofficial marketplace. I don’t want to keep anyone from doing so and welcome the generosity displayed.
However, I would like to prevent some disappointment among those offering the modules. The point is that in my view the likelihood that Fairphone owners will take on these offers is very small for this reason:
The Fairphone 3 was only introduced in late August 2019. As a consequence, an overwhelming percentage of FP3s and FP3+s are still under warranty (2 years). The only ones that have no warranty anymore are devices that had an accident that the user is responsible for (e.g. most cases of water damage). As a consequence, under normal circumstances the demand for used and working “old” camera and top modules can almost only result from users who voided their warranty and have issues with their camera and/or top module. I think the number of those users is rather limited.
You might think of users who have issues with their old modules that are still covered by warranty and yet are intentionally foregoing a replacement module they are entitled to under warranty because they prefer a used and working module from the marketplace. But honestly, I think most will want to go the official way and contact Fairphone Support for a replacement module.
So be prepared that there might be very few “fishes to bite” on your offer. Most likely things will only change in this regard once the warranty period of the first FP3s expires in September 2021.
Another idea: Consider donating your retired and functional FP3 modules to a Fairphone Angel who might be able to use it with other Fairphoners seeking help.