I've used G2A along with Green Man Gaming to get steam keys and you must do your due diligence and be your own detective look at reviews of the websites, check the rating of the site/individual seller, check their pay systems, examine their help pages like will they go the extra mile and help you get a refund if the seller isn't up to standards. Games Planet is one of the good guys, I purchased Dying Light 2: Reloaded Edition and even received another game for free on top of it: Hard Reset Redux. I can also confirm that this is the base game and the DLC that's downloaded along side it.