TZer0

100% as I probably will never need more platinum ever.

I’m sitting on a stockpile of relic parts and I can just… sell some off should I need some.

Saryn, purely due to how the frames are accessed.

Mirage is acquired through a quest you’ll do at some point anyway, Saryn is from a slightly annoying boss to run in Sedna (requires you to do arena points to gain points which can then be spent to access the fight).

Just generally, if in doubt, pick the one that is hardest to get.