He says it right after returning from the store. Like "I bought this bag of 12 tortillas, I only need one for this burrito, obviously I would be using the rest for other things".

Sure. Tortillas can indeed last for quite a long time without any particular extra effort. Those 11 unused tortillas account for $4.39. We'll take that off of the total.

The cost of the singular burrito has now been reduced to ~$30, which still seems rather expensive.