Price is a cliff, capability is a slope
Official input price per million tokens, and the share of planted sightings each model finds, both against prompt length; the 256K line in both panels.
Official input price, $ per million tokens
$0
$0.40
$0.80
$1.20
64k
128k
192k
256K
320k
256K price line
$1.20, a 3x step
$0.50, a 1.25x step
$0.40 on both models below the line
Whole-request repricing: the step applies to every token, not only the ones past the line.
Sightings found, rare-event count, thinking off
0%
25%
50%
75%
100%
64k
128k
192k
256K
320k
256K price line
qwen3.7-plus, tier at 256K, 3x
qwen3.5-plus, tier at 256K, 1.25x
Three runs per point; needle recall was 100% everywhere.
Measured through the Synthorai gateway, 2026-09-01 and 2026-09-02, salted prompts, thinking disabled. Prices from Alibaba Model Studio, Singapore list.