Sharing a home loan between 4 people

Hi all

Are there any limitations in purchasing say an $800,000 property (with a $250,000 deposit) with 3 other people? i.e can 4 people sign up for a $550,000 mortgage? My wife and I along with our aunty and uncle are seriously considering buying a beautiful large home in the inner city, and just quartering the repayments. Thus living close to our work places, in a great location and then we will just quarter (or half since we are 2 married couples) the profit when we sell?

Does anyone see any problems with this? and apart from the obvious (sharing a house) why aren't other people doing the same? or are they??

any feedback is appreciated!