Those headphones turned out to be fakes in the end: https://medium.com/bolt-blog/how-it-s-made-series-beats-by-dre-154aae384b36
There is no way that parts are worth $17. You could propably buy those headphones from chinese oem for about $5/piece if you order a lot of those. Actually I don't think the parts are worth $17 in the authentic one either. I'm not saying that to mock beats. Most headphones would be worth close to nothing if those were mass produced in china and you leave out money that went into r&d, marketing, taxes, markups for manufacturer, wholesaler, retailer etc...
By most heapdhones I of course mean "normal" headphones. I'm sure production expenses get more expensive fast when you are building headphones with more complex designs. Most headphones however are like the ones in the article. Beats, skullcandy, low end sony and philips and so on... Not that regular $200 headphones have that complex designs either...