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.
I'm not going to do the whole split here. If you want, watch the video. If you don't want to, just take my word for it that there's plenty of leftovers besides the tortillas.
If there are more burritos in the future, then: I eagerly await Episode 2: One More Burrito [from last week's funky leftovers]