Well, if eveyone is equal skill-wise, then:

With 710,800 chips and a $1788 prize pool, the equity for each chip is only about .0025. And with a $45 buy-in, you need to get over $45 worth of chip equity to make it a +EV play (at least, I think I'm doing that calculation right. Maybe someone else can make sure). This would be right around 18,000 (without doing anything in depth, since I don't have a calculator with me). Which is right near what you said, so it looks like we're either both right, or at least on the same train in the wrong direction.