Claude Sonnet 5's Introductory Pricing Expires August 31. Your Cost Model Doesn't Know That Yet.
11 days from now, Sonnet 5 goes from $2/$10 to $3/$15 per million tokens. A 50% increase across the board. If you built session budgets, cost estimates, or routing logic around the introductory rate — and you probably did, because it was the correct price when you set it — your cost model breaks on September 1. Not because of a bug. Because the price you hardcoded was always temporary. This is a…
Claude Sonnet 5's introductory pricing ends on August 31. Prior to this date, cost models relying on the $2/$10 rate will be inaccurate after September 1. The price increase from $2 to $3 per million tokens applies broadly. This change is different from gradual price drift where rates silently change over time. The increased price becomes effective instantly on September 1 if models are not updated.
Hardcoding rates like sonnetInputPerM: 2.00 will now be incorrect. Session budgets calibrated to the old rate will cover fewer tokens at the new rate. Capacity planning and routing decisions based on the old price may need to be revised. The fix is to update the pricing registry before August 31. Adding an expiration date to the pricing registry helps catch impending changes.
Monitoring should alert teams to the expiration before it occurs so they can adjust budgets and routing logic. DeepSeek also announced a price increase with no set date yet, requiring similar vigilance. Model pricing is not static configuration but a versioned input requiring regular validation. Tools like ai-costguard help surface these changes early to avoid billing surprises.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
