I've made a change today.. probably will fix it because it handles currencies (default or member language/currency). Try it yourself. Open applications\raffles\modules\front\raffles\view.php and find:
/* Generate the invoice */
$invoice = new \IPS\nexus\Invoice;
$invoice->member = \IPS\nexus\Customer::loggedIn();
Change to:
/* Generate the invoice */
$invoice = new \IPS\nexus\Invoice;
$invoice->currency = ( isset( $_SESSION['currency'] ) and in_array( $_SESSION['currency'], \IPS\nexus\Money::currencies() ) ) ? $_SESSION['currency'] : \IPS\nexus\Customer::loggedIn()->defaultCurrency();
$invoice->member = \IPS\nexus\Customer::loggedIn();
Let me know if it fixes, otherwise I will take a look closer.