Just a personal opinion ... postpone buying an air condition until you're positively sure you can afford it.

There is the old saying that "What doesn't kill you (and the kids) will only make you (and the kids) stronger", of course it doesn't always apply, but is possible to survive even if it's hot.

In addition to the cost of buying and installing the aircon, you also have to consider extra costs in electricity and maintenance.

In the winter time though, dependent on how you heat the house, it may be profitable using the aircon unit for heating.