Austrian company Frey Wille does exquisite enamel work and did the enamels for Hermes until fairly recently. They are well known for their bangle bracelets, and this is a pretty example. Part of the Alphonse Mucha series, it is called Libussa. I believe these retail for about $800-1000, but you can often find vintage pieces well priced on Ebay. See this one here.