Planner/worker split, some basic math on what it actually saves

Recently, Luna dropped its pricing by about 80% and DeepSeek shipped V4 Flash as a stable release, but it’s hard for people to understand whether splitting your planner off your executor is actually worth it. Below is some basic math.

​

For context on why I bothered, before this I was on Sol xhigh for everything and a 20x subscription was lasting me about two days. The only reason that was survivable at all was Tibo handing out resets, and once those stopped you're on your own.

​

A good rule of thumb is that if you're using say a planner/worker split, roughly two thirds of what you delegate is going to touch code and the other third is read only probing. Roughly, out of 113 worker runs over 13 tasks, 33 of mine were read only.

​

The setup I ran first was codex desktop with Sol planning and signing off, and codex cli underneath running deepseek as the executor. That works, but through cli you're basically building your own subagent scheduling and buying a second pool of quota on top. Opencode go is cheap, its still a bill.

​

In real $costs at about 3.174 billion worker tokens/month, luna is going to cost about$86. Comparatively, the same tokens all on Sol is going to be about $2,151. But you'd need to run the workers somewhere.

​

To measure whether the split pays, calculate cost of tokens versus your cache rate. The average distribution of your usage for delegated work is going to be 97/98% cached input tokens, with the rest split between non cached and output. The coordination overhead increased proportional to how many workers you run at once.

​

The main reason it comes out that far apart is that the cache tokens are about 1/25th of the equivalent pricing at the top tier. If your use case is significantly different wherein you are mostly generating the tokens, and not using caching the distribution will change.

​

On the coordination side, each delegation reported back to the main agent about 12.2 times on average, needed 0.98 follow up runs and got force interrupted 0.23 times, with 85.8% completing cleanly at least once. All of that is tokens you're paying for that aren't the work.

​

I should say I ran no controlled comparison at all here, this is all subjective. I havent seen quality drop off and read only probing, log analysis and running scripts are all fine to delegate. In practice the sub used to die in 2 days and now goes about 4-5.

​

Check me on my math if I'm wrong or not, curious about people's experience with running workers this way.