you need the will to make it happen, like actually happen. People have lost their hopes very early in this business. Dedication. Commitment. Drive everything is necessary for this business. But you need to have certain principles and ethics to make it work.

For the technicalities, you would need

• Coders
  Digital Marketers
  UI/UX peeps
  And a whole of other skillful people
  

As to answering the second part of the question - ‘The cost’ to make an online casino.
Well, again there are so many factors that act as the parameter to come up with the cost.

The complexity of the project
What are the things that make the app more complex? The language used in the backend, bitcoin integrations, and similar stuff.

Timeline
The time is given to the said game development company for the completion of the project.

Features
The more features you want, the more it will cost you.

So, yeah such a casino will cost you around $10,000- $60,000 depending again on the type of development company that you employ.

P.s. If you are open to suggestions then I would like to suggest Inoru as a Casino game development company. These guys have 12+ years of experience in game development and are correctly dabbling into Bitcoin payment integration.