Considering the Cosmos' controller tracking is totally defective, this should be a free upgrade. Otherwise HTC are basically saiying "Hey, remember how we lied to you and ripped you off lol? Well pay us hundreds of dollars to fix that for you! 😄❤️"
Like, shit, at that point there's 0 reason to not just get the Valve Index which, unlike the Cosmos, isn't broken out f the box.