Filter the download title in the email to include the price, and quantity. EDD 1.9+ only

gistfile1.php

<?php
function sumobi_custom_email_receipt_download_title( $title, $item, $price_id ) {
	$price 		= $item['price'];
	$quantity 	= $item['quantity'];
		
	// only show quantity if quantities are enabled
	$quantity = edd_item_quantities_enabled() ? ' (quantity: ' . $quantity . ')' : '';
	// append price and quantity to title
	// Download Title – $50.00 (quantity: 5)
	$title .= edd_currency_filter( edd_format_amount( $price ) )  . $quantity;

	return $title;
}
add_filter( 'edd_email_receipt_download_title', 'sumobi_custom_email_receipt_download_title', 10, 3 );