Seems that you can at least buy a Quantum SA.45s Chip Scale Atomic Clock for a mere $928: - https://www.microsemi.com/products/timing-synchronization-systems/e

Seems that you can at least buy a Quantum SA.45s Chip Scale Atomic Clock for a mere $928: - https://www.microsemi.com/products/timing-synchronization-systems/embedded-timing-solutions/components/sa-45s-chip-scale-atomic-clock https://www.microsemi.com/products/timing-synchronization-sy... - https://www.digikey.com/product-detail/en/microsemi-corporation/990-00123-000/990-00123-000-ND/6153768 https://www.digikey.com/product-detail/en/microsemi-corporat...