Price filter with included taxes

price_fitler_taxex.php

<?php
// If prices include taxes
add_filter( 'wpc_set_num_shift', 'flrt_set_num_shift', 10, 2 );
function flrt_set_num_shift( $value, $entity_name ) {
    if ( $entity_name === '_price' ) {
        // Let's imagine that tax is 10%
        // The final price will be
        // $price_with_tax = $price + $price*0.1;
        $value = $value + $value * 0.1;
    }

    return $value;
}

add_filter( 'wpc_unset_num_shift', 'flrt_unset_num_shift', 10, 2 );
function flrt_unset_num_shift( $value, $entity_name ) {

    if ( $entity_name === '_price' ) {
        // $price_with_tax = x + x*0,1
        // $price_with_tax = 1.1x
        // x = $price_with_tax/1.1
        $value = $value/1.1;
    }

    return $value;
}

?>