For US FBA, aged inventory 12–15 months now incurs about $0.30 per unit per month, up roughly $0.15 from prior levels, or around $6.90 per cubic foot, whichever is greater. Items aged 15+ months move into a higher tier of about $0.35 per unit per month or $7.90 per cubic foot, making long-tail, slow-moving SKUs significantly more expensive to leave in fulfillment centers.
