# Hidden Costs That Inflate Your Bill: Tool Use, Structured Output, Thinking, Web Search and More

> Source: https://sukruyusufkaya.com/en/learn/token-ekonomisi/gizli-maliyetler-tool-use-structured-output-thinking
> Updated: 2026-05-14T14:44:11.569Z
> Category: Token Ekonomisi & LLM Cost Optimization
> Module: Module 2: The 2026 Pricing Landscape
**TLDR:** Items not on the pricing page but real on the LLM bill: tool definitions added to input, structured output prefill, reasoning thinking hidden output, web search tool $30/1K, vision detail mode 9× zam. We open the invisible corners of the bill.