ohh its just so many knifes and i dont know how to price them :D
General normal ratio right now is 1:130-ish, up to 1:150, and sometimes lower.
It's all really based on how patient you are.
So, to keep it simple for urself.
Take A bowie knife marble fade, check steam market current lowest listing, take that x ratio you feel okay with paying/are looking for.
and you have ur ratio.
So say the knifes 450 bucks, 450 x 130 > ur number.