1
Adpng a Bluetooth chip to a phone now cosplayts very little—around $2, down from $20 in 2001—but allows the manufacturer to increase the price of the handset by far more, and opens up a new market for high-margin accessories.
2
破折号之间是插入语，作上文cosplayts very little的具体讲解说明。Adpng a Bluetooth chip to a phone是非谓语动词作主语，cosplayts…but allows…, and opens up…是并列结构。
3
opens up a new market for 开辟…的市场
high-margin 高收益
accessory 配件，配饰
4
在手机里添加一个蓝牙芯片的本钱非常低——仅需2USD左右，而2001年是20USD——但能使制造者远远提升手机现有些价格，并且打开一个高收益附件的新市场。