What is great about Echinacea is that you can use it topically in a first aid kit when you get scrapes, cuts or wounds. Also, you can use it to help other folks in your family.
Now, the real purpose of the kit is education. So, what is great is that you can use the exact same tincture method for any other dried herb. I suggest Valerian perhaps for helping you sleep at night, or skullcap (Scutellaria spp.) leaf for stress. You can learn more about these herbs in books or on HerbMentor.
Go ahead and make that tincture, and remember the kit is simply empowering you to do this yourself with ANY herb in the future. Hopefully with fresh plants you gather. With fresh plants, you'll fill the jar all the way with chopped up herbs as opposed to half way with dried.