A rough estimating heuristic for landed shipping/logistics cost on a new product order: budget about $2 per unit for an order in the ~800-unit range (China-to-US freight, customs, FBA prep). Tariff changes can shift this gauge meaningfully and should be checked before relying on it.
One FBA-vs-FBM comparison supplies concrete competing figures: FBA shipping runs roughly $3+ per unit, versus $4.50–$8 per unit via UPS/USPS under FBM. At 1,000 units/month, a $2/unit gap between the two options equals roughly $2,000/month in profit difference — a scale-dependent argument feeding FBA vs. FBM (Fulfillment Model Split)'s case for FBA once volume is meaningful.
One source quantifies the heuristic directly: a $2 per-unit shipping cost gap between FBA and carrier-based FBM shipping translates into roughly $2,000 in monthly profit difference at 1,000 units sold — "$2,000 difference in total profit that could be back in your pocket if you utilize something like Amazon FBA."