How to reason with a hungry five-year-old

Nicholas is going through a particularly difficult food-aversion stage.  Basically, he'll eat sesame chicken and pineapple smoothies.  That's it.  Today, we ordered pizza.  He cried.  He begged.  He refused to eat in a most pitiful way.  But I didn't budge.  I understand food aversions very well.  I even understand cravings.  But this is getting ridiculous.  And expensive.

Nicholas:  If I can't eat sesame chicken, I can't eat.  I already had three smoothies today.

Me:  Well then, you're going to be very hungry because I'm not spending $11 on sesame chicken tonight.

Nicholas:  But you just spent $20 on pizza!  Eleven isn't more than twenty!

Me:  But I fed six people with $20.  If everybody's dinner cost $11, I'd have to spend $77 on dinner.

Nicholas:  No, everyone can get what they want for $31.  See?  It's much less than $77!

Something tells me that Mike would have been so impressed with the quick calculation, he might have ordered sesame chicken.  But I didn't...