Hi KC - the shortest answer is that it's a comnination of additional features not available on the base Forester that creates an overlap in pricing. The XV Crosstrek Premium includes the following items as standard equipment that are not standard on the ‘14MY Forester 2.5i:
• All-Weather Package
• Roof Rails
• Privacy Glass
• 17” Machined Finish Alloy Wheels
• Exterior Cladding
• Fog Lights
• Removable Rear Cargo Tray
• Paddle shift switches
• Sliding center armrest
Hope that helps.