I have a like-new AquaMaxx ConeS Q-2 In-Sump Protein Skimmer. Works like a champ. I currently run a slightly bigger version on a different tank. $200. Cleaned and ready to go.
https://www.marinedepot.com/AquaMaxx_ConeS_Q_2_In_Sump_Protein_Skimmer_In_Sump_Protein_Skimmers_for_Aquariums_Reefs-AquaMaxx-UJ00157-FIPSIS-vi.html