That seems challenging to do with a writing/note taking app like this. First, what would the pricing tiers be based on? Word count? That would just be another way of saying token. Number of documents created? That puts you at risk of long unprofitable documents. Google Sheets doesn’t really have this problem because the incremental cost of storage is relatively cheap. Tokens on the other hand are not cheap.

How do you price based on value without a corollary to tokens? If you charged $40 for this service then maybe you don’t provide enough value for the casual user who does the occasional school report. On the other hand you may be unprofitable for the doctor that decides to dictate all of her interactions every day or the author who dictates an entire book.