If no one buys them, you might want to consider donating them to the volunteer @angels_ghent (about Fairphone Angels: 👼 The Fairphone Angels Program and Map (Local support by community members)).
Note: By releasing only two Torx T5 screws, you can detach the motherboard from the Rear Module (see https://support.fairphone.com/hc/en-us/articles/360035880131-Fairphone-3-Repair-price-list-and-FAQ-Cordon) that is not available in the Fairphone spare parts shop and might find someone interested, too.