Can I get the the paid dlc of R.U.S.E without paying 400 from a third party seller? Can I...

Hello Mills, this is Manuela!. I'm an Independent Advisor and community user like you ready to assist with this.

Getting that DLC is not easy in these times. You can try checking some third party stores to see if a seller have it listed. But even if they have it, probably is going to be expensive if you want to pay for it

we can assist you with keys purchased from unauthorized third-party sellers.

Hi Raynner,

Thanks for keeping us up to date on the issue. In this instance, the code should be redeemable. I would definitely contact the seller and get it refunded. Then purchase the game through a reputable seller. You can even get from the Microsoft store as digital.
There is nothing Microsoft can do with codes sent via third party or individual sellers.

Thanks,

Brad

Buying keys from unauthorized third party sellers is a violation of TOS and can lead to account and console bans

G2A is also an unauthorized third party seller, purchasing from such a place can lead to account and console bans