Claude Cost optimization。Pricing比較(per Mtok input/output): Opus 4.7 $15/$75・Sonnet 4.6 $3/$15(-80% cost)・Haiku 4.5 $0.80/$4(-95% cost)・Use case別選択: Opus = Math/Science/Complex Code/Research・Sonnet = Daily coding/Refactoring/Documentation/Standard Q&A・Haiku = Customer support/Voice realtime/Simple Q&A/Translation・Cost reduction techniques: Prompt Caching(-90%・cached input)・Batch API(-50%・24h処理OK時)・Model downsizing(Opus → Sonnet適時)・Extended Thinking selective(Reasoning task限定)・Streaming(faster perceived・cost同)・Subagents(separate context・total token効率)・2026年 enterprise budget管理 Sonnet主体 + Opus complex limited。