If it's as busy as I hear anecdotally, then clearly there's high demand from the locals.
Raising the price for the non residents seems the best way to raise a bit more revenue, and keep it from becoming inaccessible and over run by non-locals.
$120-140 is far less than other accessible Tour courses cost. (Sawgrass,Scottsdale,Torrey, Bethpage(reasonably close), Pebble,Spyglass, The Greenbrier, Doral, PGA National etc.)
and I'd venture a guess that the course is of higher quality than at least a few on that list.
Seems like a reasonable decision to me, and allows non locals a chance to tick a box or two.