Not $250,000 but $160,000

It can be interpreted two ways.

First, it could be, as Iggy states, that Dan is trying to fool him. In other words, if Dan tells Iggy they only got $160,000 and they're splitting it 50/50, he gives Iggy $80,000 and pockets $170,000 himself. I don't think this is the case though.

The second way to interpret it is that the papers sensationalized the crime, because a quarter of a million dollars sounds a lot more sensational than $160,000. This is far more likely, as Ms. Mitchell confirms it when Iggy questions her about how much money they got away with, shaking her head 'no' when she's asked, "It was a quarter of a million, wasn't it?" And then again at, "Two hundred grand?"

Darth_Chocolate: If you look in the Trivia category of the movie, I realized the Frank Gorshin's ("Iggy's") "money guessing", started at $250,000 (500 x 500). Second guess was $200,000 (500 x 400 = 20% decrease of $250,000). Third, $160,000, (the amount Dan told him) equals 400 x 400 & 20% decrease of $200,000.