Took a look at the container slowly filling with used wheel weights that I have access to twice a year. Much Fe(iron) weights in the bucket. Iron are less cost compared to lead and businesses servicing tires need to make a living too. At the local scrap yard the large box of used wheel weights had some lead but again appear to be increasing in iron weights. Read one post that a scrap yard had stopped taking wheel weights because the majority had turned to iron and was no longer worth there effort to process.
So here is the question: What is the next source of low cost lead like wheel weights used to be?