As I recall there were two main different runs/publishings/sets.
One was a one-volume hardcover addition that included most of the nations involved (including the Confederation of the Rhine, etc.).
The other set was two separate volumes in paperback that were essentially the same broken down into France and allies and client states and everyone else in the other. This set had a few nations the hardcover does not if I am remembering correctly, like Sardinia…but I am not 100%.
It is not, for example, the Nafziger collection that has OBs for each and every battle. But, it will give you the basic army strengths at any point in history as well as units added during various years.
If you want a breakdown of the armies involved, by year to year or at least important sub period to sub period of the Napoleonic period that includes how brigades, divisions, corps, regiments, battalions and companies were organized as well as good OBs for all nations involved, to me, this is a must-have book for the Napoleonic enthusiast.
With that said, I do not know what the market value is, but in good plus condition, considering how long this has been out of print, I would expect that is not outrageous.