Make less usefull/weaker weapons and equips less expansive.
Example:
Iron Slug is not better than a Polaris...so why they cost the same?
So this is the deal(only for 5 star recipes/alchemy)...
Weapon and equips:
Weaker/Less usefull:20.000 crows/640 CE cost
Medium/Common: Betewen 21.000 and 24.000 crows/700 CE cost
Stronger/Usefull/ More abilities: 25.000 crows/ 800 CE cost
Weapons are to be balanced, which would, hypothetically, make every weapon equally as useful.