taking it to the post office

On going to the post office to mail a present:

Me: I’d like to send this parcel, please.
Post Office Lady: Let’s see if it fits through the letter slot.
(it doesn’t).
POL: Oh. Well now you’ll have to send it as a parcel, instead of a letter.
Me: (having anticipated this scenario). That’s okay.
POL: It’s just that it’s a lot more expensive.
Me: I know.
POL: I mean, a LOT more expensive. (she examines it). If it were a letter, it would be a dollar ninety-two. As a parcel, it’s nine dollars.
Me: That’s okay. It is a parcel. It’s not a letter. It would have to be a couple of millimetres thick to get through that slot. This is over an inch.
POL: Can you make it any thinner?
Me: Well, no, because that’s how thick the thing in the parcel is.
POL: Because it would be a lot cheaper.
Me: Yes, I suppose it would. But that would involve not actually sending the thing that’s in the parcel, and just sending a letter instead. In fact, if I didn’t send anything at all, it would be free. So maybe I should try that next time.
POL:…
Me: nine dollars, then?