Hi and welcome,
This sort of question is best asked in the community forum rather than in the developers forum.
But in answer to your question
A: It will be all over the community forum when someone has a ballpark figure for running a vault. Basically we have no idea at this time. Also it will be very dependent on the network operations. If spare storage space in the network is low then you’ll get more but if spare storage is high then much lower returns.