LLM Cost Optimization: How We Cut Reply Generation from $0.011 to $0.0009

When we shipped the first version of AI-generated replies for HelperX , each reply cost us about $0.011 in API spend. That sounds tiny until you multiply by 30 replies per slot per day times 200 active slots: roughly$66 per day, or ~$2,000 per month. Not catastrophic, but enough to eat into margins on the smaller plans. A year later, we're spending$0.0009 per reply — a 12x reduction. Same model providers, similar reply quality, same throughput. The savings came from four optimization layers st