What's the additional cost to you for using a decanter versus a bottle?

It's essential to weigh the cost implications of both options. Decanters will provide a more luxurious and premium feel, which can enhance the perceived value of your cognac and potentially justify a higher price point. However, they tend to be more expensive to produce and may require more intricate packaging and shipping considerations.

On the other hand, bottles are generally more cost-effective and easier to handle in terms of production and logistics.

It's difficult to give you a more precise answer without knowing more about your cognac brand and its positioning. Furthermore, you should look at the competitive landscape and see what the market is doing. Always zig when the competitive is zagging -- stand out from the crowd and turn whichever option you're going with into a strength.