If you find some unique buttons they can sell individually on Ebay. Just run a search for buttons. Also reenactors are always in need of authentic bone buttons. So if you've got any of those, they can be sold. See the Special Threads section on identifying ivory for photo examples of bone and how to identify it. Most of what I can see in the photo looks like plastic though, so your best bet might be to resell them as a craft lot.