WPT - replace sale price with regular price if no sale price set for product

product-table-replace-regular-with-sale-price.php

<?php

// Assuming you have cf:_sale_price as a column in your table...
add_filter( 'wc_product_table_data_custom_field__sale_price, function( $price, $product ) {
    if ( empty( $price ) ) {
        $price = get_post_meta( $product->get_id(), '_regular_price', true );
    }
    return $price;
} );