Element put money and time into R&D, marketing, and which your pals from China don't.
Your estimates of cost and price are anecdotal, and the development and marketing costs of an iPhone case are worlds apart from 'paintball parts', aesthetics, fit and finish notwithstanding.
Obviously, Element has provided value by designing a popular case - otherwise, why would people be rushing to buy the design? Element also did the work to ensure that their case didn't interfere with signal, unlike the knockoff.
This is why we can't have nice things. An American company does the innovation, a Chinese company copies it with none of the overhead and dubious quality, and you reward the ripoff with a purchase. Nice.
I'm just guessing, but you might whistle a different tune if you made paintball parts for a living, devised some neat feature and after hours and hours of testing and CNC work refining it, put it up on the market and a month later found it on paintballswill.com for less than your cost to make it. "lol black market products for the win!"