I've been in Oaxaca for a year, up in the hills in the Huatulco area. Was looking to start a community with some others. We didn't really have a plan and it has mostly dissolved but it may come back to life in some form. We built a couple casitas there and have installed irrigation and planted some gardens. All this done without a written agreement and no ownership, haha. I am still living there while deciding how to proceed. I may complete the land purchase of 3.5 hectares and build a few things as a refuge and keep the gardens going.
Land ownership in Mexico is complicated it seems. There is a restricted zone of 50km from the beach where foreigners can't own land directly. Then, there is a lot of communal land which you can "own" but it's within the communal structure. I don't know all the details on that but it's good to be aware of.
Come for a visit if you are in the area or planning to travel a bit to check out Mexico.