It all depends on your joint income.

My wife and I together earn around 150K p.a. If we paid tax as individuals, it would be around 2-3K a year cheaper where we are, as it is not offset by a lower tax for married people. It is often referred to as the "Heiratsstrafe" (or marriage penalty). With the increase in de-facto relationships, two-income married couple are being more and more penalised.

They are looking into changing the law to equalise this discrimination, but I don't expect anything in a hurry.