WooCommerce Tiered Pricing - Price By Quantity Plugin empowers merchants to provide discounts for products based on quantity with more effective way by

Guide your users to the correct purchase of some products and set minimum or maximum quantity for them

The WooCommerce Advanced Quantity plugin lets you control how the quantity field for products is working.

WooCommerce Min Max Quantity & Step Control plugin offers to control of all products or specific products with minimum, maximum and step of quantity. With

WooCommerce Custom stock Quantity Reduction plugin enables a multipliers stock per product variation to sell single, multiple boxes, case, bundles and packs.