There was already a lively "old violin trade" in the 19th century. Even Leopold Mozart (1719-1787) advised his students to prefer old violins to newly built ones.
In the last 50 years, Italian violins in particular have increased enormously in value. One particular example is the violin by Antonio Stradivari called "Lady Blunt".
The instrument was auctioned at Sotheby's in 1971 for a record price of 84,500 pounds. In 2008, the Nippon Music Foundation paid 10 million dollars for the instrument. In 2011, another auction at the Tarisio auction house generated proceeds of 15.9 million dollars.