For people wanting to purchase Prime Access: Buy it through the Warframe website, NOT through Steam, especially if you are outside the US. : r/ Warframe
Warframe: Prime Gaming Verv Collection
Amazon.com: Warframe Lightning Pack [Online Game Code] : Video Games
Warframe: Rage Pinnacle Pack DLC | PC | CDKeys
Warframe: Amazon Prime Day Bundle
Amazon and Mountain dew are doing a promotional thing with warframe with free plat codes (for ps4 only I believe) : r/Warframe