To maximize margins, focus on the Total Cost of Ownership (TCO), which includes the unit price, freight costs, customs duties, and insurance. Negotiate tiered pricing structures where the unit cost decreases by 10-20% as volume increases beyond the initial Minimum Order Quantity (MOQ). Additionally, consider consolidated shipping if sourcing from multiple vendors in China to reduce logistics overhead, and utilize FOB (Free On Board) terms to maintain better control over shipping rates and schedules.