Toorak 27 - Eden Brae | Cost Help ?

We are looking to build later in the year most likely with Eden Brae at this stage.

Just waiting for some land releases to open up in our area before making the jump.
But we are just wondering the additional costings involved as first time builders it's a bit daunting.

The cost of the Toorak 27 is around $278,000 , and their essentials package is around $334,000 from memory.
Then we were looking at the Luxury Living package for around $7000 and the façade I think was around $8000.

So total is $349,000 without any discounts or additional upgrades applied.

But my question is, how much should we be allowing for other things ?
I've looked through the forums and everyone seems to say 100K on top ? is that 100K on top of base or essentials pricing ?

I guess we are just a bit unsure of what we will require, we want the timber / laminated flooring so I assume that is extra and by the looks of it the downlights would be extra, no ?

We really wanted to set the budget of $680,000 (includes land) , land is around 280-300K.
We'll probably do the landscaping separate.

Any help would be much appreciated on our Journey ! or perhaps if it's out of our budget need to look at other builders or designs.

Thank you

Hi, I am building Bristol 30 on a tight budget. You can minimise upgrades to structural options that can be done later.

There's two Eden Brae groups on Facebook with heaps of posts about costs for individual upgrades and stories about what people have prioritised. I prioritised ceiling heights, full height tiles, wider garage, extra windows and removed flooring to be done after handover to save money.