Dave you get what you pay for. I have shopped around a bit and found both plastic and metal clocks. The best source I have found is
https://www.klockit.com/all-departments/clock-inserts.html?gclid=CjwKEAiAlNbEBRCv9uy4j4SWrgwSJAB5MqJFMF12Yk3mbfiZjYdfHmbaktWF038OoD2IiYkfElT4DxoC9Cjw_wcB
They carry a wide variety of sizes, styles and price points. Hope this helps.
DW