How Much Does KV Cache Actually Save? A Real Look at Chinese LLM Cache Pricing

Most developers know KV cache reduces costs. Few have actually modeled how much, at current pricing, cache hit rate moves the needle on their bill.

Take Qwen3.7 Plus on RouteAI: standard input at $0.24/M tokens, cache read at $0.048/M — 20% of the normal input price. If your application has a high proportion of repeated prefixes (stable system prompts, long document contexts), and you're hitting 60–70% cache rate, your effective input cost can drop below $0.12/M.

Two habits that dramatically improve hit rate: keep your system prompt static, and front-load document context at the top of each message. Combine that with RouteAI's already-discounted base price, and the effective cost per token gets very low very quickly.

Worth modeling explicitly if you're running any kind of batch processing or RAG pipeline with consistent context structure.