100 square meters is very, very big unless you are almost unthinkably wealthy. Or at least it is in my neck of the woods.

100 m2 is only a square about 33 feet on a side. Big if you live in a high rise in a city but you don't need to be unthinkably wealthy in any area that has woods. The plot of land that my house sits on is 800 m2 and I am most certainly not wealthy, let alone unthinkably so.

10 meters by 10 meters is very, very big?

Afforestt was started by the Toyota engineer in OPs citation.

But this is very costly.