This weekend I upgraded from 2012 to 2015 iMac. If you can get 2012 for $200-300 then, go for it, especially if someone upgraded HDD to SSD; otherwise, save the money and buy something newer. It looks like the one you linked is listed for $700 Australian Dollars. I would spend additional $300 and get brand new M1 Mac mini and monitor of your preference and you will have a system for many years to enjoy. if new Mac mini is too, much look for a used one.