The cowrie-shell radical. Originally a pictograph of a marine cowrie used as the earliest Chinese currency. Highly productive — the 'money/value' marker of the language: 财 (wealth), 货 (goods), 购 (buy), 贵 (expensive), 贱 (cheap), 贸 (trade), 赔 (compensate), 贷 (loan), 资 (capital). Spotting 贝 immediately suggests something economic.