More than I had thought:
For instance, the
real price (in 1988 prices) for the basket of the entire Top 100 list [for the U.S.] was
$4,313 in 1988; $3,132 in 1993; $2,533 in 1999; and $2,421 in 2004. That is nearly a 44% decrease in prices
from 1988 to 2004. At the same time,
there was no significant change in the quality of the wines on the Top 100
Here is much more information, from Karl Storchmann.