ThinkPad X1 Carbon systems are business-focused laptops where reliability and keyboard/port wear are common decision points. Repairs are often cost-effective when the issue is a known wear item like a battery or a noisy fan, because those fixes can restore a stable work machine for a fraction of replacement cost.
Replacement becomes more attractive if there are signs of motherboard instability, repeated USB-C charging failures across docks/chargers, or structural damage to the lid/hinges that compromises the display. Consider how critical uptime is: if you rely on the laptop daily for work, recurring intermittent problems may justify replacement earlier even if a single repair is under the threshold.
When the device is near the typical lifespan and needs multiple expensive parts (battery plus display or board), replacement usually reduces risk and downtime.