I like the idea and could see myself using this. After trying the tool a bit, I liked it and had some thoughts.

I think your landing page communicates well, it was pretty clear what it was going to do. The only thing I wasn't sure about is if the tool is also meant for teams larger than one. Then I would need to be able to enter different costs based on different roles, but I'm not sure if that's the target audience.

You said the project is half finished, so I assume you have tons of small UI improvement ideas already... But I would really prefer a different method of adding new lines/tasks over just adding every type on add :), for example a dropdown with an add button.