Earlier quoted context omitted.
"they already use fairly exclusive materials for their hardware" What, exactly? As someone who has used an iPhone 3, 4S, iPad 3, and many other mobile devices, I'm really struggling to think of a material that is "fairly exclusive" to Apple.
They have their own aluminum alloy made specifically for the phone. Custom plastics, dyes, colors, etc. They've got enough scale/buyer power to optimize to the n-th. Not to mention that the A-series processor is Apple only, they get early access to the best screens, etc.
http://www.theverge.com/2012/10/17/3515158/htc-shows-off-stu...