I would include the adapter as they are not a big ticket item anyway and buying in bulk reduces the cost even further. It also isn't bad to have a spare because if one will fail, it will always be at the worst possible time. I would also include the SD card, especially if like the conductor, some cards don't work with it. Some people may have SD cards that they may want to use but if it doesn't work how does the builder know if it is the card or the Panther itself that is the issue. I can see where people like to save money but I find it much easier to have the kit complete, especially where you know that the components all work together. You could also make these items options but that is more work for you but if your willing .......