Buy old property or house and land package

So we're moving from NZ to Melbourne and recently sold our home there. Looking at our options for our family home and using the 5% scheme:

If we buy a old property for 800K
40K Deposit + 43K stamp duty and other expenses

If we buy a house and Land package 800K
40K Deposit, also 10k grant if we get under 750k.

I have a cousin, who did house and land package when the house was already in construction and got possession within 3 months. The builder is very reputed and workable in many options.

At this points, the stamp duty savings seems to be a lot and also there will be cash backup, no reno costs etc. What would you recommend?