1. To understand potential room rates you need to do your market research and check comparable local hostel type listings to see what they charge @Richard2944
2. The only one who will know whether it's likely to be a viable business is yourself by putting together a profit and loss budget with all your set up and one off costs and projected income
How do you know the STR market is not over-saturated?
How are you planning to manage cleaning of communal areas?