The longer a whisky is aged, typically it is more expensive. However, aging only happens inside the wooden barrel. The whisky develops more flavours due to interaction with the wooden cask. There is diminishing returns to ageing the whisky longer.
This isn’t what’s happened here. The whisky was stored in bottles. These bottles shouldn’t cause any ageing. However, these two ideas can be conflicted.
The value of this whisky is a taste of the past. A way to physically experience some history. People with an idea that things were better in the past may want to believe this was a better whisky.
I would guess this isn’t going to taste better. Improvements in manufacturing, quality control and knowledge of whisky probably make a better whisky today. Any high end whisky is going to be better. However, these same processes make low end whisky cheaper and probably worse.