Going rate?
Borg Warner anti spin LSD shown is a friction tapered cone type. Non rebuildable. Unless you know its history, best to stay away. TBH your better off buying a rebuildable clutch type LSD from Dr Diff. Unless your playing Ricky Racer with drag slicks, no need for a 489 case unless you gotta have if for bragging rights. Most A bodies came with a 741 case. A 742 is most common. Both 741, and 742 cases are sufficient for most performance applications