Down Under dues
It is always worth asking agencies to see what they have to offer. If it is a buyers' market, they'll probably expect you to cover registration fees.
Although GTCE fee is only pound;30, overseas teachers who want certification in England have to pay more, so the pound;226 fee may not be exceptional. Try direct contact with schools, but it may limit where you can work and possibly the type of work you're given, even after having paid for the registration yourself.