Costing price increases when features are suppressed

I have to admit I'm a little confused.  I'm trying to work my through a mill costing exercise, and I ran across something I thought was working backwards.  The part file I have has a port cut into it, and when I supress that feature the cost calculation goes up.  When I unsupress it the cost goes down. How is it possible that adding work decreases the price?

SolidworksGeneral