Actual costs of launching an app.

Hi, I have an app idea that would connect multiple businesses with users. It would work similarly to Airbnb or Uber. Users would create a project, for example- building a house (I don't want to share my full idea; the house is just an example). The app would allow users to book all services through the platform, including plumbers, carpenters, bricklayers, etc. On one side, there would be businesses; on the other, customers who want to book their services to see if a professional is available, their costs, and their ratings. I hope that makes sense. What are the costs? including patent, UX and UI, development.