I exported all my chatgpt conversations and calculated total costs I would have incurred were I using their API (gpt-4o) model.
My "total" costs, across all conversaitons from entire history of using it for almost 2 years, came out to just 34$!!! In the same time I have been paying them 20$/month, amounting to 20*20=400$!
I'm an average ChatGPT user using it mostly for ptogramming related tasks.
Here's the script I used to calculate (this is adapted from their own index.html file when you get exported chat data):
https://gist.github.com/freakynit/e8b2c173290f210a1cb7644a6e41752c