AI Pricing This Week: DeepSeek Gets Cheaper, Claude Sonnet 5 Gets Pricier

DeepSeek V4 Flash has exited preview at $0.14/$0.28 per million tokens, outperforming its larger Pro model on agentic benchmarks with an 82.7% score on Terminal-Bench. Meanwhile, Anthropic's Claude Sonnet 5 introductory pricing ends September 1, with the headline price rising from $2 to $3 per million tokens, but a new tokenizer adding up to 35% more tokens, making the real-world cost increase closer to 2x.

Two pricing stories dropped this week that are worth a pause if you're building on LLM APIs. DeepSeek V4 Flash left preview at $0.14 / $0.28 per million tokens input/output — and it's beating its own larger Pro model on agentic benchmarks, hitting 82.7% on Terminal-Bench . That's a smaller, cheaper model outperforming its own bigger sibling on agent tasks. Anthropic's introductory pricing for Claude Sonnet 5 ends September 1. The headline price rises from $2 to $3 per million tokens — but the bigger change is under the hood: a new tokenizer adds up to 35% more tokens for the same text. Combine the two and the real-world cost increase is closer to 2x , not 1.5x. If your stack leans on frontier models by default, this is a good week to: Cheap isn't always what it looks like on the label, and expensive doesn't always show up as a sticker price change — sometimes it's a tokenizer. Sources: llm-stats.com, aitoolsrecap.com