500K is a lot of money. More than 99 percent of people make in a lifetime. I would say, the goal should be to accomplish this without much money. Any money spe

500K is a lot of money. More than 99 percent of people make in a lifetime. I would say, the goal should be to accomplish this without much money. Any money spent will add to the co2 footprint. (you can buy a lot of gas/concrete/coffee/meat/plastic/clean water... for that kind of money.)