WU charges a flat fee. And I don’t think it’s 50 euros. They also do the conversion as you can ask the type of money received, usually dollars, or the local currency. It’s about 8usd last time I used it.
Apart from simply wiring it from a European to a Taiwanese Bank account: Friends. If you have someone you trust, and who needs the transfer vice versa, just agree on a course (say, Google) and transfer privately. You transfer the money to her European account in EUR, she transfers the equivalent amount in NT to your Taiwan account.
I think it’s actually cheaper to WU if the money is not that much. International transfer usually have fees from both parties bank. And possibly an intermidiate bank to go between them.