I would suggest most could retire reasonably comfortably on $60k pa. By this I mean have a roof over your head, eat quite well, and have the basic necessities and the odd luxuries of life.
However, there is a difference between living comfortably, and having the power to grow your life.
When I hear people speak of "greed", I believe they see the world from the viewpoint of "scarcity". In other words, their view of the world is of limited resources, and that one person taking a lot will mean less for others.
My own view of the world is from that of "abundance". I believe there is more than enough to go around - however resource is required to distribute what is available.
This comes back to your purpose in life - what you are out to achieve. If what you want to achieve in life is sitting atop a mountain meditating, then I agree, you do not need much material posessions, nor instruments of wealth. However, this is not the vision for all people. Some people wish to be able to do more for others, be it family, friends, relatives or total strangers. I would suggest that for these people, they will need more resources than those with "smaller" ambitions.
I must stress that I find there is nothing wrong with how big or small your ambitions and visions are - they are yours.
Suppose you went forth, and bought all those properties - hundreds of them. Are you being greedy? I would suggest you are providing not only accomodation, but busines and livelihood for a great number of people - property managers, tradies, gardeners, builders..... who will then spend there earnings on other business etc etc. I find nothing profoundly wrong with this.
Suppose you got extremely wealthy from your ventures, and decided to build an monumental compound of a house - again, is this greedy? How many people did you need to employ to make this dream of yours a reality? Architects, builders, council people (oooh...
)....
Perhaps what IS wrong is where people deliberately limit themselves from realising their own potential. If you CAN own hundreds of properties, or run a huge business, and have millions in income, perhaps it is wrong to NOT achieve the full potential in life you were born with.
Cheers,
The Y-man