Flying Tiger is a Danish design store — they’ve recently opened a location in New York, and when I checked it out recently, I found that they have some amazingly cheap notebooks!
They have colorful composition books for only $2:

There are also 3 sizes of hardcover journals, 4×6″ for $1, 6×8″ for $2, and 8×12″ for $3.
They come in a variety of solid colors and patterns.

It seems like the kind of store where the products are frequently changing, so it will be interesting to see what other notebooks come along over the next few months…