Everything is better homemade. I suspect that this is also true of vanilla extract. It takes 2 months to make so only time will tell.
You need only three things- 3 vanilla beans, 1 cup of plain vodka or rum, and a glass jar with a screw on lid
Sterilize the glass jar and lid in boiling water for ten minutes. While the jar is in the water, use a sharp knife to cut each bean in half longways. Measure out your liquor of choice. When the jar is done, remove from the water very carefully and dry it off. Combine the vanilla and vodka, making sure everything is submerged. Place the jar in a dark area for 2 months. Every week, shake the jar gently. This will help the flavors incorporate into the alcohol.