Heading overseas - sell or rent?

Harsh asks:
(updated on Tuesday, February 26th 2013)

We are moving to Sydney permanently with our three-year old toddler. We bought a house in October 2009 for $340,000 and we'd currently expect $400,000 selling it (including agent fees and other selling expenses). Our chances of coming back to New Zealand are very slim. Should we sell the house or rent it? Looking at the real estate in Sydney I am not sure if we'd be able to afford a property in the near future. We currently have a loan of $232,000 and a $10,000 flexiplus. We are paying mortgage of about $443 per week and expecting a rent of $450 per week. We planning to increase the flexiplus to $30,000 so that we cover our immediate expenses like insurances and repairs (if we rent the property) plus our initial settling costs in Sydney.