I happened to come across a couple of promo codes that might interest people (last checked 16/11/2017 please inform me if any are broken so I can remove them):
Heatsword Orokin Catalyst slot: FREESWORD
Feel free to come and play warframe https://www.warframe.com/signup?referrerId=566d38c13ade7fc5727b2442
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The Telos Boltor is an exclusive version of the Boltor available only from the Arbiters of...