Rage 2 has been received somewhat positively but certainly didn't have a stellar start. It seems like the trend will continue with the upcoming DLC, Rise of the Ghosts that is due on 26 September 2019 that will cost roughly $15/ €15/~ £12.
Rise of the Ghosts will include a new story, the eponymous faction, a new region, one weapon, ability and one new bike. It will cost 1.500 Rage coins, which you can't purchase directly since the currency is sold in packs of 500, 1,100, 2,500 and 4,500.
Therefore, it's hard to gauge the exact price of the DLC since you can either purchase three packs of 500 for a total of $15/ €15/ £12 or go for one of the more expensive packs in order to get a lower per-coin price but then you would have excess currency. However you try turning this monetisation model, it's not ideal and it's only going to further provoke the already frustrated player base.
Anyway, the Ghosts faction used to be kind of a big deal in the wasteland once upon a time apparently. They were ruthless, vicious, tactical and cruel - basically raiders with a hint of brain activity. Authority Wars started raging on and the glorified raiders disappeared as they seem to have found religion.
A woman named Iris is the person who turned out to be their prophet and she led them to the Overgrown City where she brainwashed them and experimented on their bodies which led to Ghosts having powerful nanotrite abilities. After the raiders got their taste of superpowers, they are now back to the wasteland in order to conquer and pillage once again.
Walker will get a new ability called Void and the Feltrite Laser Launcher in their arsenal while attempting to quell the raider uprising. There is also the new Ghost Motorcycle that players can come across in the Overgrown City, which is the new map, and bring it back to their garage if they want to keep it.