The problem is the set was made in the 70's. Anytime up through the early/mid 60's and it probably never would have even made it to Ebay, but changed hands privately for more than $30K.
All the big Dunnie collectors I know put great stock in the company changes that occurred then. The briar source to finish matchup stopped being a shop rule (Sardinian for Tanshells, Algerian for Shells, Calabrian for Bruyeres, and Corsican for Root Briars); the stain recipes changed; some models were "streamlined/updated" to make them easier to produce; stems got chunkier; and QC in general took a nosedive. It's a milder version of the Pre and Post eras to Barling collectors.