Since I don't ski in Colorado much, I haven't paid that much attention to the RMSP. Looks like the price goes up July 1 for 2016-17. The RMSP+ ($569) includes a few days at a short list of places, including a few in New Zealand and Japan. Get 6 days at Steamboat, 3 at Crested Butte, and 3 at Alyeska. RMSP ($499) is a pass for Winter Park and Copper. Senior rates start at 70.
For those who want to wander more, the MAX Pass ($649 stand alone, $249 add-on) is also noted on Ski Colorado since it includes Copper, Winter Park, and Steamboat. "*Qualifying season passes include full price purchases of: RMSP+, RMSP, Route 40 Pass, WPSP."