Sean
The clubs which are on the "If it's Tuesday it must be Troon" rota are of course sustainable, but I don't think they can raise prices unthinkingly. Where they can falter is if they don't adequately reinvest their cash flow in the course and/or divert too much of this cash to non-golf related projects, i.e. new clubhouses which cannot be justified by any sort of rational financial feasibility study.
As for the great unwashed mass of clubs, the only real attribute which they share is their diversity. Those that have a strong and stable membership and a positive brand image will survive, particularly if they can find and exploit a niche in the golfing market. As with most businesses, those which can create an attrractive ethos at either the high or low end can even prosper while those trapped in the middle will be increasingly vulnerable. There are examples of each in the 15 clubs within a 15 mile radius of where I live. (NB--the population in this catchment area is no more than 150,000 people, which raises other serious issues if you do the simple maths.....).
I am increasingly coming to the opinion that someone travelling into the future and landing in the Scotland of 2025 would very possibly say:
"Yes, Jim, it's golf alright, but not as we know it......"
Rich