The Link only costs 30 bucks at full price on Amazon and it's been that way for months. Also my local dollar store sells perfectly good 6ft HDMI cables so I already have the ability to stream everything my computer can do onto my old TV screen rather than Steam only. Added bonus, it works with my existing keyboard, mouse, and controllers.
Steam can be great, and lowering the price of the connector is nice, but don't forget you're paying nine bucks for something that's going to push another fifty dollar controller sale on you to play games you already paid for and can already play just fine. And even if Steam Link can let you play videos across it, it's impotent to know Smart TVs and Window 7+ already come with the software to do that.