Frontier intelligence is needed only to plan and decompose a task, so cheap workers under an expensive planner cut cost nearly tenfold.

groundsAgent swarms and the new model economics, Cursor

Few moments in a large task genuinely require frontier intelligence, such as the original decomposition, the design decisions, and certain trade-offs. Once a frontier planner has collapsed the ambiguity into a detailed, explicit instruction, less expensive models simply have to follow it.

groundsAgent swarms and the new model economics, Cursor

In the run that used GPT-5.5 for both planners and workers, the workers alone cost $9,373. In the run where Opus 4.8 did the planning and Composer 2.5 did the work, the entire worker fleet cost $411.

qualifiesAgent swarms and the new model economics, Cursor

The Fable 5 planner ran up a slightly smaller bill than the Opus 4.8 planner, despite roughly twice the per-token price, because it used far fewer planning tokens. But the Fable run's workers went through several times as many tokens, and the run as a whole came out substantially more expensive.