Spent and farm your marks before TTK here's why; I got maxed marks on all characters I'll just fill up the vault with materials because I'd rather have them then some stupid reputation consumables. 1200 marks makes for 2400 materials divided by four makes 600 of each material. I got 300+ of each already in the vault so I'll be around 1000 of each, I think that will do for awhile. Say you need between 10/20 again per upgrade perk it will cost around 100 materials to fully upgrade a weapon or gear item if you got 1000 of each it lets you upgrade about 40 items seems enough for at least the first couple weeks into TTK So I'd say; horde people!!