steel scrap is around $0.05/lb and has been under $0.02 before. at that point what do you really use for fill that won't stand out? copper is cheaper than nick

steel scrap is around $0.05/lb and has been under $0.02 before. at that point what do you really use for fill that won't stand out? copper is cheaper than nickel and people bring in plate and hide weights in it all the time