2x8GB is ~$150. 2x4GB is ~$50[1].
Apple is charging $200 for a $100 bump in component costs. 100% markup is excessive.
[1] http://www.newegg.com/Product/Product.aspx?Item=N82E16820233...
We nerds need to accept that we ate not apple's focus anymore. Just spec your machine high, pony up lots of money, enjoy the shit out of it.
Anymore? It's never been Apple's focus