got sick of the insane Claude API bills running agent loops in Cline lately. Decided to actually track a standard 10-turn debugging session on a 10-file python repo. starts at 42k context, scales to 51k by turn 10.

Assuming a pretty optimistic 90% cache-hit scenario, the premium-model cost still adds up if you run this kind of loop all day. Without caching, it gets ugly fast. Here is what the same session looks like:

Fable 5 is the new premium option in this comparison, but on the same workload it still comes out to about $1.38 even with a 90% cache hit. The math is brutal. paying $0.69 per session for Opus in an open source model workflow is a fast track to bankruptcy for a solo dev. I've been testing MiniMax M3 and DeepSeek as an alternative lately. M3 lands at around ten cents in the cached scenario. I haven't done anything fancy with retrieval here: it just chews through the whole \~40k-token repo without me setting up a separate RAG layer, and the context cost stays low enough to keep the workflow simple.

GLM-5.2 is another 1M-context option, but I haven't used it enough yet to say much about its coding consistency.

Still trying to figure out if the drop in micro-coding quality is worth eating right now to save the cash.

Claude API is WAY TOO EXPENSIVE, Token cost breakdown for open source workflow alternatives