Focus on output costs first — output tokens are typically 3-6x more expensive than input tokens, so optimizing response length has the biggest impact on total cost. A model that costs twice as much per input token but generates 50% shorter responses may actually be cheaper overall.
Compare models on cost-per-quality, not just cost-per-token. GPT-5.4 Mini is the sweet spot for most production workloads — it delivers 90%+ of GPT-5.5 quality at 85% lower cost. Reserve GPT-5.5 and o3 for tasks where the quality difference directly impacts user experience or business outcomes.
For high-volume applications, the per-request cost difference compounds rapidly. A $0.005 difference per request becomes $5,000/month at 1 million daily requests. Use this calculator to model your specific usage patterns across multiple models before committing to an architecture.
