Funny you should ask – last weekend's auction results provide a handy guide.
Melbourne or Sydney – take your pick, there's a $4 million-plus mansion to fit the bill in either city.
A three-bedroom, ocean-side house in the south Sydney suburb of Blakehurst took the title for most expensive auction result of the weekend – with the hammer dropping on a final bid of $4.8 million.
The property, with views across Kogarah Bay, was touted as having the "unique opportunity to capitalise on a sprawling 1,365 square metres", according to listing agency McGrath St George.
Other features include a backyard running directly up to the water's edge, guest accommodation above the garage and a kitchen with a walk-in pantry and original fireplace.
Down in Melbourne, a five-bedroom house on Barkers Road in Hawthorn East fetched the state's highest auction result: $4.36 million.
The 4.5 bathroom Victorian-style home combines "graceful period style, contemporary modern flair", according to listing agency VICPROP.
The property also features a parquetry floor entry, chandelier lighting and manicured gardens.
It's a tough choice – which one would you buy if you had a spare $4 million or so?