Time for a little bit of a check of where I am with the whole "You can complete the game for free" thing I was running.
So I'm about 100 hours in with 0 real world money spent. I've got about 150+ platinum left. This is going to take a hit with the frames I'm building and also with the weapons I want to keep for future use. Just for quality of life improvements so I'm not constantly juggling weapons when I'm levelling stuff up. I'm guessing it can be done, but the frustration of having to constantly do inventory management is annoying, so it'll have to be that way at some point.
Ember, Equinox, Frost, Hydriod, Ivara, Nova and Valkyrare frames that I've got to get that I have access to but have not gotten all the pieces of yet. This is going to cost 140 platinum. There's also 4 more frames from the Tenno Labs that I'll have access to in the coming weeks, so that's another 80 platinum. You might have noticed that this platinum price exceeds what I'm given for free. Now you can sell bits on the market for platinum to other players, but I'm not going to do that.I just don't have the inclination to do that and when I finally run out of platinum I'll report on that and put money down to finish the rest up.
However, it must be noted that you don't need those frames. I'm just collecting them for completions sake. It wouldn't surprise me if you could do the entire game with Excalibur or Volt. Not Mag though, since she's terrible comparatively.
Lua, Neptune, Pluto, Sedna, Kuva Fortress, Eris, The Void, The Derelict and to some extent Plains of Eidolon are challenges I've yet to do. When you look at it I'm just over half the way through. There's planets I've not completely finished, either through being stuck on certain parts (hello Pandora) or just nodes that I've not done because I've not had the people online to do them or when I have we've been doing other stuff. It might be worth having a bit of a house keeping session at some point to tie up all those loose ends and farm for the frames we're missing currently.
All this is based on the game as it is now, although I'm certain they'll add more stuff to it at some point. If I was a betting man I'd say that maybe the open world part of the game would slowly be rolled across the planets that could accommodate it.
I do think it's feasible that you can go from one end of the game to the other without spending a penny. I don't think they're blowing smoke up players arses when they say that.