I mean, I guess if it doesn’t sell, they just bale it up again and off it goes to its original destination.
Their only cost is the initial sifting and warehousing.
And even then, they might be able to sell their pre-sifted inventory at higher prices baled-up for export.
Books aren’t too different:
https://www.nytimes.com/2007/06/23/business/23shortcuts.html