In a tool loop, Opus 5.5 answers in fewer turns for less money
Cost per run at list prices. 4 multi-hop questions over a small codebase, 3 repeats per arm, 12 runs per bar.
Bars show the mean run cost; the label gives solved runs and the median turn count.
Opus 5.5, default
$0.0326
12/12 solved, 4.0 turns
Opus 5.5, low effort
$0.0330
12/12 solved, 4.5 turns
Opus 5.5, max effort
$0.1087
12/12 solved, 5.0 turns
Opus 5, default
$0.0519
11/12 solved, 5.0 turns
Turning effort down saved nothing: the model took 1 extra turn and re-sent the transcript again.
Max effort cost 3.3x the default and solved the same questions. Measured 2026-09-23.