Before giving you some sort of "figures", do you know where to start?
You should consider this comment, for me you don't have to use a lot of bitcoin to start a casino, you can use other people's money, don't get me wrong what I meant is get some investors, present the project to them, pitch the price for investment, give them the sweet spot profit (not too low % and not too hgh % or they will think its a scam). Like what Robert Kiosaki said, "Only lazy people use their money".
It is better to ask potential investors first rather than settle for what you have and ending up having a substandard casino site, where you will earn very little because the competition is already very tough.