I've got TWO Seagate external drive enclosures that are brand new, never used. They were purchased to farm the internal drives (which were removed, carefully). Only the plastic/metal housing, controller board, mounting hardware, USB3 cable, and power transformer remain.
These were 4TB drive enclosures, so the logic board is designed to handle large capacity SATA2 drives with a fast USB3 interface. Opening the enclosures required a bit of elbow grease, so a few of the plastic clips are broken, but this should NOT affect reassembly.
Both kits for $35, or $20 each.