Hello Snoop,
I don't know what the search engine traffic is for "property buys", but I own www.propertysale.com.au and "property sale" is searched for over 200,000 times per month on Google Australia. I'm planning to put a free, for-sale-by-owner website up soon.
In my opinion, the dominance of www.realestate.com.au for anything related to real estate makes domain names with highly searched, alternative keywords such as property even more valuable.