I am eyeing the Girard Perregaux Chrono 30 anniversary (ref: 49480). I found a dealer on Chrono24 who is willing to sell it. How do I go about making sure it is real? This is my first time investing in a finer timepiece and wanted to know the process of making sure I do not get scammed. Is it better to purchase a new watch from an online retailer like jomashop? The Tag Heuer Carrera Automatic (WAR211B.FC6181) is my safe "buy new" option. Which is the better route? Are both these routes flawed?
Background: I would like an elegant sports watch (up to $3000 usd).