Offering quantity-based prices would be one of the most effective and powerful methods to urge buyers with very few convincing actions needed.

Quantity-based tier pricing for WooCommerce: tiers by product, category or catalogue, shown on the product page, cart and checkout.

Bulk and tiered quantity discounts: percentage off, amount off or a fixed unit price per tier, with a live pricing table on the product page.

Volume pricing tiers for WooCommerce. Set quantity discount bands and show a server-rendered pricing table on product pages. No jQuery.