ConfigOverrideItemCraftingCosts=(ItemClassString="PrimalItem_WeaponStoneHatchet_C",BaseCraftingResourceRequirements=((ResourceItemTypeString="PrimalItemResource_Thatch_C",BaseResourceRequirement=1.0,bCraftingRequireExactResourceType=false),(ResourceItemTypeString="PrimalItemAmmo_ArrowStone_C",BaseResourceRequirement=2.0,bCraftingRequireExactResourceType=false)))

That's an example of how to make the Hatchet require 1 thatch and 2 stone arrows to craft.

so you have to find the emgram entry name for the item you want to change the cost of.. as well as the engram entry name of the specific resource you want to make the item cost.

PrimalItem_WeaponStoneHatchet_C < is the entry stone hatchet
PrimalItemResource_Thatch_C < is the entry for thatch

Theres a list online of all ark items/resources - I'm doing this for the first time, so not sure if this will work with mod items, but i imagine it should.. So find the entry for nightmarebullet, put it where hatchet is.. and find the resources you want it to cost and replace thatch, etc.