Paid budgeting tools generally charge between $80-$100 per year, which can be a good value if a budgeting methodology works for you and saves you money. This, however, limits the size of the market significantly.
Fion is free because we want to make it easy for as many people as possible to track their spending across all their cards.
We will expand on this topic on our blog, because it's a very important issue that all free personal finance apps need to address.