Naive About Mondavi

[pergamum]

Do you you have any idea of a price for this wine (1988)?--The Wine Spectator wine index offered no help on this one.
I didn't purchase it; rather, it was a gift from a friend whom I asked to not go "overboard" in buying a birthday gift pour moi. I'm concerned that she might have gone a little over the top on this one, and would like to compensate her.