It’s a rate not a quantity. $2/litre sounds expensive to me, in Toronto you can find milk for $5.78/4L.

Bags of 1% and 2% Nielsen are about $6/4L, or about $1.50/L around the GTA.

Cartons get more expensive at $3.49/L from the same brand and same fat percentage, for some reason (I doubt the packaging overhead's that much).

In Calgary, I can usually get 1 gallon (~4l) for about 6 dollars. However, if you get organic or anything, you easily go past 2$ / liter (CAD).