Are you talking about value of current kits you might have in stock,really depends on supply and demand,is it still available or out of production,how badly someone might want it,if dealers have it,your probably going to have give some one a bargain to sell it.
If your talking some "collector kit" who knows,there might be a list,but what a book says you can get for it is different then if you can actually find someone willing to buy it at that "book price".