STH pricing can be viewed on the site linked below. As a 20 game plan holder, I have access to full STH pricing for any extra tickets purchased. If I have a free morning I'll drive by the ballpark and save on the service charges, but most likely at 10 on a weekday morning, I'll have to work around my meeting schedule just to make sure I'm at a computer at the moment when they go on sale.
http://washington.nationals.mlb.com/was/ticketing/season.jsp?tab=seating_pricing
