I assume you meant to say they’re not above the equator, which I didn’t actually know until now.

We can find the new length by simply multiplying the equator total by cos(latitude), since circumference is linear to radius.

For subtropical jet streams, latitude is around +/-30 degrees, so our adjusted price comes out to around $950k.

For polar jet streams, the latitude is around +/-60 degrees, bringing the price to $555k.

Extra note: The jet streams can reach speeds of >100mph, so I don’t think our poor little toothpick and plastic film kites will survive!