Amélie have access to Bamboo?
I created this post
https://permies.com/t/149278/Building-Homestead-Community-Costa-Rica
I'm now in Panama :) Puerto Lindo, Linton Bay Marina. It's a day drive to get to your location for a visit.
I thing that Bamboo huts would be great to build. Offer workshop and generate income while building a hut. Then it can be rented out for recurring income :)
Basically offer a course for 2weeks for $2k. Get 10 people and make $20K. Then you buy the bamboo and supplies to built a hut.
Offer a course every month or two and build up your property, and the one next to you.
I like to learn more about the land, size, location, what is on it, etc.