Matt,
I don't see recreational golfers paying $100 to play a round of golf on any kind of regular basis in most areas of the country. The course in Albuquerque that gets the most play BY FAR is Arroyo del Oso which is the best of the three municipal courses and is maybe $30 give or take.
When Blackthorn and Warren in South Bend, IN got their fees up to that $75 range with cart on weekends their play dropped off rather significantly. Now I think one can get on either for $50 or under most of the time and from what I have heard play is back up. Both of those are pretty nice courses for the money.
If you compare only golf courses then courses like those are pretty good deals in terms of value for the money. If you compare even $75 courses to other types of recreation then the value drops off significantly.
All that said, economically you are right in that $100 has become somewhat of a cutoff for new affordable golf courses. I think that's a problem, however, if we actually expect people to continue to play.