The additional cost for an egg roll varies between $.20 and $.60. In every case you get the exact same egg roll, and the exact same amount of work goes into getting it to you: they just take one and stick it on the side of the plate your dish comes on.
Now think about this: rather than just putting on the menu something like "Egg roll $.40 extra" somebody had to sit down and think about exactly how much extra the egg roll should cost for each lunch special. And then had to direct the printer to print an extra column.
Why in the world did they do this? Any guesses?