Change price based on customer choices

Hi

You could use woocommerce_before_calculate_totals hook for this purpose, you can put something like this in your functions.php

function calculate_cart_total( $cart_object ) {
    /* additional price that has to be added */
    $additionalPrice = 100;   

    foreach ( $cart_object->cart_contents as $key => $value ) {
        /* Check for the value ( or it could be any condition logic ) */
    	if( $value['wccpf_your_fields_name'] == "your expected value" ) {
            //change the price
            $quantity = floatval( $value['quantity'] );
            $orgPrice = floatval( $value['data']->price );
        	$value['data']->price = ( ( $orgPrice * $quantity ) + $additionalPrice );
        }
    }
}
add_action( 'woocommerce_before_calculate_totals', 'calculate_cart_total' );