It appears that Classic is no longer a flat $25 surcharge over Economy; it apparently depends on the route. The fare difference does not appear to be linked to availability, nor distance.

Many routes now have a $30 increase over Economy, some have a $10-$20 difference, and a few still have the $25 additional cost above Economy.

All routes checked are direct flights.

Is this somehow related to the introduction of SELECT seating or just another way to increase revenue?