To optimize costs, negotiate based on Weight vs. Surface Area; natural leather is often priced by the square foot, while synthetic is by the piece. For bulk orders (over 5,000 units), aim for a 15-20% discount by committing to a long-term supply contract. To ensure security, always conduct transactions through Secured Payment systems on Made-in-China.com, which hold funds in escrow until you confirm the receipt and quality of the goods. This mitigates the risk of receiving 'dry-rotted' leather or non-absorbent synthetics.