Show HN: Sunk Cost – How long until a local LLM rig pays for itself?

Show HN tool 'Sunk Cost' calculates when a local LLM rig breaks even versus falling API prices, factoring electricity cost and inference speed.

A Hacker News Show HN project called Sunk Cost models the payback period of buying local LLM hardware instead of paying API prices. Users can adjust assumptions like electricity cost ($/kWh) and API speed (tokens/second), and the model assumes API prices keep falling. Where local speed is unmeasured, it is estimated from memory bandwidth divided by bytes read per token, and labelled as an estimate.

• Compares total cost of a local LLM rig against per-token API pricing
• Adjustable inputs: electricity $/kWh and API speed in tokens/sec
• Assumes API prices continue declining over time
• Local speed estimated via memory bandwidth ÷ bytes read per token when unmeasured