I don't think that its for anyone on here to judge one way or the other whether or not its expensive - surely Mark will pitch it appropriately and if he has no paying guests then he'll know that something needs to be reviewed.
You can't compare the Ring o Bells with a travel lodge or similar, there is no comparison, and the price (if it is per room?) isn't that expensive.
In my opinion, if I were visiting Marple as a tourist I can't think of a nicer pub to stay at, the location is fantastic and the regulars in the pub would surely make you feel welcome.