Whilst what you pay for the property is lower than what you pay for a freehold property it doesn't necessarily mean a freehold property is cheaper over the long term.
The key thing you need to understand is that when you buy a leasehold property not only do you pay the mortgage on the house but you also pay the lease (ground rent) on the land. You may find that whilst you think your outgoings are lower because your mortgage is lower than you would have on a freehold property you need to add the cost of the ground rent to see if you are actually better off overall from a cash flow perspective.
The dangerous area in leasehold property is how much the lease will go up by in the future. A recent example is the Beaumont Quarter in central Auckland where the property owners have been informed that their ground rent is going up by over 400%.
There are two issues with this. The most obvious is the direct cost of the increased ground rent which in this case for the larger townhouses means the ground rent is going up from $3,900 to around $21,000. The second issue is that it is expected that the value of their properties will go down by up to 30%.
In summary the trouble with leasehold properties is the unknown future value of the land and what that will cost you in increasing ground rents over time. Also make sure you thoroughly check out the lease agreement so you clearly understand the terms and conditions of the lease before you enter into a contract.
If you are struggling to get on the housing ladder you may be better off looking at the new government joint equity scheme if your household income is under $85,000 per annum.