What should I buy with my marks? (Destiny)

by CyberKN , Oh no, Destiny 2 is bad, Wednesday, June 15, 2016, 21:02 (3328 days ago) @ Claude Errera

If I'm at all low on planetary materials, I'll visit the Vanguard Quartermaster (in the hangar) and buy some.

I think this is the best way to convert marks into faction rep.