Outsourcing software is very bad idea, why?? You get what you paid for... You can't control the project, your project gets copied all around(not good for copyright), bugs costs to fix.... Updates are not guaranteed.
Club house? More details please
It's an audio chat. Allows you to send audio messages after the moderator has given permission.
There are rooms open and all, rooms open only to one's contacts and rooms open only for those who are invited.
There are also room indexes dealing with certain topics.
Many listen to talks of VIP characters.
It is necessary to have a site with a lot of space and a lot of bandwidth.
I think that at least one (or multiples of it) tens of thousands of euros it takes in addition to the technical structure to host such a data flow (server, bandwidth, etc.)
ok on my end... I think it would cost around $12.000-$25.000 ( $25/hr - 60 days full time - one developer- android- ios- php ) to develop... and a monthly service for servers $50 , you can use server balancing if you need more servers and go $10 each additional . AWS , Coogle Cloud or even Digital ocean offer great deal to starters, so when you have your app running and testing will cost cheap