Precisely this.
Ever since RCBS quit the custom (& esoteric) loading die business it has become much more of a challenge to source dies for the rather more rare Nitro Express and Black Powder Express rifles.
Yes, ch4D does sometimes have stock on hand or will custom make dies, but if not readily in stock it can be up to a 2 year wait for dies.
Hence the price of those relatively scarce used loading die sets. IMO the $225 (OBO) asking price is not out of line at all.
- Mike