the $15 model that bills like $31. Kimi K3 lists at $15 per million output tokens. on the artificial analysis intelligence index it spends 130M output tokens against a 63M median. 67M above the median. the effective rate is about $31. same suite. same list rate. $1,950 in output instead of $945. per-token price is the wrong unit for agentic. nearly every published comparison still uses this metric, yet it hides a 2x spread in what a task actually costs. verbosity is trainable. in one post-training pass, DeepSeek’s V4-Flash-0731 cut output tokens 12% (234M → 206M) and gained 10 index points. the 28M tokens it dropped were never buying the score. it’s still 3.3x the median, it just moved down a tier. so does verbosity pay? on a median-verbosity workload at list rates: Fable 5 $3,150, K3 $1,950, Opus 5 $1,575. K3 beats one and loses to one. on measured cost per index task: K3 $0.86, Opus 5 $2.03, Fable 5 $3.15. it beats both. Opus doesn’t run at median verbosity either. before you commit to a model, compare what each task costs you. full data in V1.1 of State of Open Source AI. link in the comments.
The 'median-verbosity workload' bit is what got me. If verbosity is trainable, per-task cost becomes a moving target every time a vendor ships a post-training pass. How do you compare models without redoing the benchmark each release?
Tokens per task is the unit that matters for budgeting, and the 130M vs 63M median gap shows how list price alone misleads. I'd be curious how much that verbosity figure varies run to run on the same suite, since an effective rate without an uncertainty range is easy to over-read.
I like that you're pricing per task instead of per token, and our own runs back up the conclusion, but they also suggest the verbosity multiplier depends a lot on the kind of work. On our tasks from late September to mid October, which are bug fixes in real repos, long multi-turn reasoning sessions and agent tasks in a sandbox, K3 actually wrote close to the median amount (about 1.2x on coding, 0.75x on reasoning and 0.95x on agent tasks), while Opus 5 used around 3.6x the median on the reasoning sessions, so K3 came out at $0.29 a session against $2.08 for Opus 5 with almost the same score. V4 Flash 0731 is an even stranger one, because on our coding tasks it went the other way from what you saw, and its average answer jumped from about 510 to 1,045 output tokens the day it shipped while the pass rate barely moved, so the cost per correct fix went up 95% at the same list price. Same build, opposite direction depending on the workload, which is basically why i started ASL, to keep testing the same tasks over and over instead of trusting one number.
Definitely, Raffi. Benchmark performance becomes far more meaningful when measured alongside the resources required to achieve it.
read the full report https://stateofopensource.ai/