If you’ve driven up Route 93 North you’ve gazed at the face of Whaleback Mountain. Now sustained by a nonprofit group, it’s a fun, lovely and historic spot to ski and ride — at a deal of a price. Adult tickets come in at $40 weekday and $50 weekend and kids are even less. Pop in for the last two hours any day (on your ride up or back from another spot?) and pay just $22.