Consider a dataset with a total size of 15GB on your local storage, such as AWS S3.
Running one (1) operation on this dataset, such as a .sum or a .sort_values, would consume 15GB of processed data in Terality.
As soon as you reach the next Terabyte's limit, you’ll be charged for it. For example, if you run eighty (80) operations on the same 15GB dataset, that would consume 15GB*80=1.2TB of processed data in Terality. You'll be charged $19.
Once you've crossed the 2TB mark of processed data, you'll be charged for it, hence, an additional $19 (total of $19+$19=$38 for 2TB of processed data.