Keep in mind when buying vintage you'll almost always be buying second hand.

Typing the name of the cologne you want into a google search engine and adding words like "vintage" or "original formula" can lead to results. 

 A sealed box is usually your best bet if your new to buying vintage. 

Third party websites like eBay. Mercari, or Etsy. If you navigate with caution, can be excellent outlets for finding good vintage! 

Check the sellers feedback, see if they have other vintage listings. Look for sellers that specialize in the sale of vintage. 

Keep in mind, most name brand stores and websites will be usually be selling you the newest formulation of a fragrance, unless they specify otherwise.

Be aware that some sellers use stock photos, you may not be getting the same bottle that's pictured Look for listings with multiple pictures, or ask the seller for additional info.

Estate sales and some perfume shops even have vintage sections if you ask. Let your nose be the judge!

A short ingredient list on the box is an easy way to tell if it's a pre 2001 batch. 

 Most importantly, realize part of the fun with buying vintage fragrance can be the chase!