Apply filters to price?

Hi. I’m trying to apply a simple global filter to prices displayed in all instances (simple product page, shopping cart page, emails, etc.).

I guess that this is possible with a small apply filters function but it isn’t working for me (I’m not a code master).

I take some basic code from wpsc_calculate_price function in product-template.php

Can anyone help me to get in the right direction?

This is the code that I add to my functions.php file:

function wpsc_modify_price() {
	global $wpdb;
	$product_id = get_the_ID();
	$sql = "SELECT <code>post_id</code> FROM ".$wpdb->postmeta." WHERE <code>meta_key</code> = '_wpsc_price'";
	$product_id = $wpdb->get_var($sql);

	$price = get_post_meta( $product_id, '_wpsc_price', true );

        // simple test
	$price = $price*100;

	$price = apply_filters( 'wpsc_price', $price, $product_id );
	return $price;
}

Thanks in advance!

https://wordpress.org/plugins/wp-e-commerce/