I didn't understand the significance of the following paragraph from the story ' The Gift of the Magi' by O.Henry -
" For ten seconds let us regard with discreet scrutiny some inconsequential object in the other direction.$8 a week or million-a-year - what is the difference? A mathematician or a wit would give you the wrong answer. The Magi brought valuable gifts, but that was not among them. This dark assertion will be illuminated later on."

Question

I didn't understand the significance of the following paragraph from the story ' The Gift of the Magi' by O.Henry - 
" For ten seconds let us regard with discreet scrutiny some inconsequential object in the other direction.$8 a week or million-a-year - what is the difference? A mathematician or a wit would give you the wrong answer. The Magi brought valuable gifts, but that was not among them. This dark assertion will be illuminated later on."