Off-Topic Tuesday: how much is your penny candy?

I love The Simpsons.  I want to write about The Simpsons.  And I don't want it to always be sports-related.  And since Chris stopped doing our last Tuesday segment, we have an opening in the schedule.  And so we begin Off-Topic Tuesday, an irregular segment to give us a forum to do Useless Non-Sports Analysis.

I'm going to start with a quick one.  In Homer and Apu, it's clear that the Kwik-E-Mart is overcharging its customers.  Observe the following exchange, via SNPP:

Man 1: I need one 29-cent stamp.
Apu: That's $1.85.
Man 2: I'll have $2.00 worth of gas, please.
Apu: $4.20.
Martin: How much is your penny candy?
Apu: [cheerful] Surprisingly expensive!

You'll notice that Apu never actually answers the question!  How much is it?!

Well -- let's take what we know and try to model it!  This is actually pretty easy -- we have just 2 price conversions in the dataset, so I'll just apply a linear relationship.  Here's what you get:

So it looks like the Kwik-E-Mart is taking in a flat fee of $1.45 for each purchase, and then it adds a 37% surcharge on the item price as well.  Net -- penny candy would be $1.47 (after rounding) if purchased in one transaction.

No wonder Apu still works there.  Even though he holds a doctorate in Computer Science from Springfield Heights Institute of Technology, the sheer margins pulled in by the Kwik-E-Mart ensure that he's paid competitively!

-rj