I would like to clarify that as a freelancer, you’re charged a sliding fee based on your lifetime billings with each non-Enterprise client. This includes all contracts you’ve ever had with that client. Service fees are the same whether the contracts are hourly, fixed-price, or projects on Project Catalog
Here is an example: On a $600 project with a new client, a freelancer’s service fee would be 20% on the first $500 and 10% on the remaining $100. Their earnings after fees would be $490.
You can find more information in this help article.