Philips SmartSleep (Deep Sleep Headband) is a wearable sleep device where comfort materials and embedded sensors are the limiting factors over time. Philips lists a 24-month warranty period for the Deep Sleep Headband, and it explicitly notes replacement sensors may have no warranty-useful context for repair vs replace.
A representative price around $399 is reasonable for a specialty sleep product sold through major channels. Repair is typically limited to external accessories (charger/cradle) or replacing sensor modules if available; frayed fabric sensors or worn contacts usually mean the core wearable is at end-of-life.
Replace is the practical choice when the headband no longer reads reliably, becomes uncomfortable due to material breakdown, or when connectivity issues persist across resets and updates. If the device is within two years, warranty support is a better first step than paid repair because many faults are in the electronics module rather than the band itself.