Just looked up, an hectare of (10,000 m^2, about 2.47 acre) is 1,102,000€ in the Champagne region

If what you’re saying is true, then an acre in the Napa valley is more than twice as expensive as its counterpart in the Champagne region. Which is weird, I’d expect the Champagne acre to still make you a lot more money

Champagne is one of the most expensive and luxurious wine in France.

Unless they are in Burgundy. 10million an acre for some nicer, but not top, parcels are not uncommon.

Napoleonic inheritance laws resulted in the continued subdivision of Burgundy landholdings, so that some wines come from tiny plots. There are lots of tiny wine producers in Burgundy. I'm surprised that plots appear on the market at all; I supposed that nearly all plots were kept in the family.

Inheritance tax force many to sell. Still it is not like a lot of plots hits the market.