DirectMaterial.com is selling lead-free brass valves. The VBB02 valve that is 3/8" sells for $4.49, for example.
Here is a quote from the email they sent to me:
Whether you are using valves for water, oil, or gas or if you are using them for processes such as brewing, sanitation, cooking, or hydraulics; Directmaterial.com offers a wide variety of options that can help you succeed. Our valves range in sizes of 1/4" to 4" and are available in Brass, Bronze, Stainless Steel, PVC, and Iron. Feel free to check out our blog at DirectMaterial.com for answers to common questions and helpful tips!
In Flanders fields the poppies blow * Between the crosses, row on row, * We are the Dead. Short days ago * We lived, felt dawn, saw sunset glow, * Loved and were loved, and now we lie * In Flanders fields. -- from a WWI poem