The cost of a genuine Kentucky Derby mint julep varies. A basic mint julep--equipped with a souvenir glass--costs $15. However, there are some big spenders out there that will dish out over $2,000 for the highest-end bourbon and a rare, etched souvenir glass! If you're wondering how many the Kentucky Derby sells each year, let's just say that it takes over 2,000 pounds of fresh mint to keep the minty cocktails flowing!