I'm not a teacher, but was considering studying it. Bit shocked to hear about the oversupply issues in metropolitan areas. That would be pretty stressful after having retrained.
Something that caught my eye in Sydney - not sure if it's happening in Melb - is the volunteer ethics teacher program for primary schools. They do want a minimum committment of a year, I think, so sounds like it might only be do-able for you in addition to relief work rather than permanent teaching. Might be worth a look.