Curious as to what your budget was to get where you are today? That's a lot of tokens. I presume you are using gemini flash?
You can add it up!
I have seen Gemini costs change quite a bit when processing very similar books from the same series lately, mainly because thinking tokens have increased about 5x. Has that has happened to you as well?
Edit: for ocr I am using about 15k-25k tokens per page, but I have a complex prompt.