And you can.
Don’t get me wrong here, I feel for everybody out of warranty and with a broken (or “very likely” broken) core module, as this is the most expensive part of the phone, and indeed you would get a new and well equipped phone for the price of the core module easily. That’s frustrating, of course.
Still, that doesn’t change the fact you could keep and repair the Fairphone 2. For years.
If there are fairphoneangels in your vicinity, they could perhaps help you determine whether the problem really is the core module.