I am looking at starting a business offering private rooms for Groups to play there RPG games. I am looking to price a private room that can seat 5-6 at $50 for 4 hours of game time. How much would you pay?
They Do . . . Occasionally
Such businesses do already exist, which means people do pay for things like that, albeit it doesn't seem ubiquitous by any means. Around here they seem to have adopted the label 'notcafé', offer a rent of a small room with a table and chairs and/or cushions, and often also give out cheap snacks and tea/coffee for free to the renters. They also tend to have a small library of games on offer (around here they tend to be skewed in favour of quick-to-pick-up boardgames, not RPGs).
Just how profitable they are is something you'll have to ask the owners.