Forestville,CA - At Bergman Euro-National Vineyards, we've been tracking vineyard values and sales of the last 60 years. Sales data show that vineyards have appreciated from 100% to 300% every 10 years in both Napa and Sonoma counties: solid evidence that vineyards are great investments in the North Coast. But we’ve learned that even the best investments can take a hit when the entire economy is turned upside down.