Facts are, firms that audit public companies globally have audit standards to adhere by. Comps are readily available to firms from many sources, such as other clients and market research. Auditors cannot just take the word of a dubious CEO of a penny stock company when providing independent audit attest services. Where I get my info, it is readily available to me as my spouse has been in public company audits for years and research is made available.
If you want to spend $5000 you can buy research. However, Citi Research has not been so gentle of all in production costs as I have mentioned, they came in much higher for the trailing 12 months for 50% of the global gold production.