How accurate is Emory's Net Price Calculator?

Hi,
I did the Net Price Calculator for my son and found the result shocking, because I paid about 20k more than the NPC estimate. What was your experience? Thanks.

When did you do the net price calculator? I strongly suspect there is currently a bug in the net price calculator for several colleges run through college board. I did Emory and got a parent contribution of $0 and total cost of $8500, even when I upped parent wages to $500,000. I got similar results at several other colleges run through college board.

The estimated financial aid that Emory gave me was around 5K more than what the Net Price Calculator gave me.