Display original price and discount when a discount code is applied.

my_pmpro_applydiscountcode_return_js.php

<?php

/**
 * Display messages of the Original Price, Discounted Price and Amount Saved when discount code is applied to PMPro order.
 * Add this code recipe to a PMPro Customization Plugin - Display messages of the Original Price, Discounted Price and Amount Saved when discount code is applied to PMPro order
 * Various classes added to strings to allow for styling - ".pmpro-discorig-message", ".pmpro-orginal-price", ".pmpro-discount-price", ".pmpro-save-price"
 *
 * [my_pmpro_applydiscountcode_return_js] Display original price and discount when a discount code is applied.
 * @param  string $discount_code    [description]
 * @param  integer $discount_code_id [description]
 * @param  integer $level_id         [description]
 * @param  integer $code_level       [description]
 * @return void
 */
function my_pmpro_applydiscountcode_return_js( $discount_code, $discount_code_id, $level_id, $code_level ) {

    // Only continue if code is valid.
    if( false == $code_level ) return;

    // Get the original level.
    $level = pmpro_getLevel( $level_id );
    // Format prices.
    $original_price   = pmpro_formatPrice( $level->initial_payment );
    $discounted_price = pmpro_formatPrice( $code_level->initial_payment );
    $discount         = $level->initial_payment - $code_level->initial_payment;
    $discount         = pmpro_formatPrice( $discount );
    // Build HTML.
    $html  = "'<div class=\"pmpro-discorig-message pmpro-original-price\">The original price is {$original_price}. </div>";
    $html .= "<div class=\"pmpro-discorig-message pmpro-discount-price\">The discounted price is {$discounted_price}. </div>";
    $html .= "<div class=\"pmpro-discorig-message pmpro-save-price\">You save {$discount}.</div>'";
    ?>

    	jQuery("#pmpro_level_cost").html(<?php echo $html; ?>);

    <?php
}
add_action( 'pmpro_applydiscountcode_return_js', 'my_pmpro_applydiscountcode_return_js', 10, 4);

This recipe is included in the blog post on "Display the original and discounted price when a discount code is applied at checkout." at Paid Memberships Pro here: https://www.paidmembershipspro.com/display-the-original-and-discounted-price-when-a-discount-code-is-applied-at-checkout/