Deploying and maintaining a Dapp, what are the gas fee expenses solely?

Lets say i have built my Dapp and i now want to deploy it to the network. What would be the gas price for doing this? (given normal non congested network activity). I guess this depends on how many smart contracts my dapp consist of? since they all need to be deployed.

And how much would the operating costs be? for example how big expenses does Opensea have for just operating their service. - except for system updates.

I am not talking about the fees the users are paying. Solely what the company themselves would have to pay.