To ensure profitability, calculate the Total Cost of Acquisition, which includes the purchase price, international freight (sea or air), customs duties, and refining charges. Since PGM prices are highly volatile on the London Fix, professional buyers often use hedging strategies or insist on pricing formulas tied to the market spot price at the time of assay. Avoid suppliers who offer 'flat rates' without referencing specific part numbers or metal grades, as this often indicates low-grade or 'aftermarket' converters which contain significantly less precious metal than OEM versions.