Is it feasible for private people to buy land in Australia?

It's completely feasible, but it must be noted that just buying a house or land can't make Australia give you any immigration qualification. In other words, you can only travel to your home or do business, but you can't legally live in Australia for a long time.

Generally, when buying a foreign passport, the buyer needs to apply to Canberra for a foreigner's purchase permit, but it is basically approved.