That's unbelievable. Inventory slots are the real end game. Just when I thought I had enough there was always a need for more. Unless you delete weapons and frames to only use the ones you like, but that's tedious and super time-consuming if you decide to switch later on. To know if you like something, you've gotta try it out first. That means deleting an item/frame to use another, then possibly deleting the one you tried for a previous one if it doesn't work out. Then a new weapon or patch might make a previously underpowered set-up viable, but you don't have space for it and so either again delete what you've been using, or ignore it and keep using what you've been since it's good enough to farm for stuff to sell. Unless you're incredibly patient, that's no way to play the game. I spend over 1500 hours on Warframe and by the time I fianally moved onto something else, inventory slots were still the most commonly bought item for me.

I traded significantly as well, but spent quite a bit of money on that game anyway. To date, it was the most expensive game I've ever played.