4 ms·That sounds slightly more expensive than plastic.by idbehold 11y agoThat sounds slightly more expensive than plastic.ceejayoz 11y agoWhy would walnut shells be expensive?the8472 11y agomaybe lower shelf-life if soaked in water?azinman2 11y agoPlastic is way cheaper than walnuts. Look at the price per pound of raw materials, not to mention only specific places in the world can grow walnuts versus plastic which can be produced anywhere.