seeking information on rare wine, or is it?

[sweetnessish]

I'm new about certain wines, and their value. Does anyone have any knowledge of a 1982 Chateau LaLagune, Haute Medoc, a Grand Crus Classe? Please forgive my ignorance concerning this particular wine. I'm versed on the region, and the methode, however I am told that this was not bottled in 1982, yet I possess a bottle. If so, how much would the bottle be sold for in an open market, and why is it so difficult getting info?