So I have been using Github copilot pro and its extremely generous subsidisation for a while now and basically view AI assistance as a critical part of development. That is coming to a close at the end of the month as they are moving to API pricing. My main usage till this point was sonnet 4.5 and then 4.6 with bits of Opus.
My main way of using these models has been with OpenCode. If you are using these agentic harnesses, you can see what your usage will roughly be with a little cli utility:
As you can see, most of that is due to Claude Sonnet and Opus. The GPT-5.5 and others we will come to later:
View attachment 1908309Which gives you how much API fees you will be paying. For me, it was about $200 USD average, which is quite a lot going up from $40 per month.
Obviously this is a problem. To help others, I will document the methods I used. The trick I found out is that you cannot really compare token per token costs between models. A model that outputs the right answer in 5x more tokens, but being 2/3 the cost per token will not be cheaper to run. To quantify this, there is a site that measures test scores vs cost to run.
View attachment 1908312
Source
This was very interesting to me, as you can see that according to this metric, GPT 5.5 low reasoning is basically equivalent at producing the same sort of results as sonnet and some of opus reasoning, but for 1/4 the price.
To me, this is a slam dunk against Anthropic's models, which is why I have moved over all my work to mostly using GPT 5.5 low reasoning.
Using a slightly shorter period, you can already see the difference.
View attachment 1908324
I will be moving over to a ChatGPT pro plan for now, and see how that goes. If it isn't enough, then we will need to switch to the $100 USD a month plan.
But this is worth the price as opposed to the $hyteshow with Anthropic who will rugpull whatever tools you like using.