All Windows Phones sold by Microsoft in the US now come with free Nokia headphones
If you want to buy the Coloud Boom Nokia Headphones separately - perhaps in a different color than yellow - these normally cost $34.99 (though they're currently discounted to just $19.99). Of course, there are plenty of better headphones out there, but you can't really complain when you're getting something for free.
All the smartphones that are now available via Microsoft Store run Windows Phone 8.1, and will be updated to Windows 10 Mobile later this year (possibly in September). Some of the less advanced models won't get all the features that Windows 10 comes with.
source: Microsoft Store via Neowin