HTC announced the second generation Vive headset last year, only to reveal that the advance in technology also means an increase in price. The headset alone costs £799, and the full kit that's just gone up for pre-order is no better. That comes with an insane £1,299 pricetag, which is is more than two months rent for some people.
The thing about the Vive Pro was that it was just a headset, and you needed to buy the controllers and basestation sensors separately. Not a problem if you already had the original Vive, but it was a pain to have to do all that if you were a newcomer. The full kit simplifies the buying process, bundling the headset with second generation sensors and slightly newer versions of the Vive's hefty motion controllers. No wireless adaptor, though, so you'll have to wait a bit longer for that.
The bundle costs £19 more than buying the headset, sensors, and controller separately, but you get the added bonus of more advanced basestations. The tracking accuracy is supposed to be roughly the same as the old basestations, but SteamVR Tracking 2.0 does let you link up more than two of of the boxes at a time - potentially increasing the size of your play space in the process. The controller don't seem to be any different, other than the fact their colouring has been changed to match the Vive Pro's blue hue.
The regular VR user probably isn't going to need to take advantage of SteamVR Tracking 2.0, so this probably isn't going to be a bundle you'll want to buy - provided you could afford it. If you have your heart set on a Vive Pro, rather than the cheaper £499 Vive (and £100 deluxe audio strap), it will work out cheaper to grab the headset and the gen 1 accessories separately - particularly if you can get the basestations and controllers second hand.
The Vive Pro does have a lot going for it after all, with improved resolution, an adjustable headstrap, built-in headphones, and more. It's expensive, though, and the Full Kit doesn't change that fact, but if you want it and can justify it the option if there. Just head over to the Vive website to order.