You’re looking to assign different unit prices based on the quantity added to Cart, for example from 1-100 price is $5, from 101-1000 price is $4.90 and from 1001 units ordered price becomes $4.75.
There are many “Dynamic Pricing” plugins out there (and the number #2 on this article would suit complex pricing rules and dynamic discounts), but this time I want to teach you a simple code to DIY WooCommerce quantity-based pricing.
As usual, comments and shares are much appreciated. Enjoy!

PHP Snippet: Change Product Price Based on Quantity Added to Cart (Bulk Pricing)
In our example, our product price is €34 and I want to apply a 5% discount above 100 units and a 10% discount above 1000 units. Screenshots for threshold 1 and threshold 2 are below the snippet.
/** * @snippet Bulk (Dynamic) Pricing - WooCommerce * @how-to Get CustomizeWoo.com FREE * @author Rodolfo Melogli * @compatible WooCommerce 3.8 * @donate $9 https://businessbloomer.com/bloomer-armada/ */ add_action( 'woocommerce_before_calculate_totals', 'bbloomer_quantity_based_pricing', 9999 ); function bbloomer_quantity_based_pricing( $cart ) { if ( is_admin() && ! defined( 'DOING_AJAX' ) ) return; if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 ) return; // Define discount rules and thresholds $threshold1 = 101; // Change price if items > 100 $discount1 = 0.05; // Reduce unit price by 5% $threshold2 = 1001; // Change price if items > 1000 $discount2 = 0.1; // Reduce unit price by 10% foreach ( $cart->get_cart() as $cart_item_key => $cart_item ) { if ( $cart_item['quantity'] >= $threshold1 && $cart_item['quantity'] < $threshold2 ) { $price = round( $cart_item['data']->get_price() * ( 1 - $discount1 ), 2 ); $cart_item['data']->set_price( $price ); } elseif ( $cart_item['quantity'] >= $threshold2 ) { $price = round( $cart_item['data']->get_price() * ( 1 - $discount2 ), 2 ); $cart_item['data']->set_price( $price ); } } }

