The type of information needed depends on if the building is being constructed in the future or if the building already exists.

Seems to me that area is massively over build or going to be overbuilt for the foreseeable future..

Nowadays many vacation homes are priced as STR businesses with profits baked into the price (with future guests expecting instagram furnishings).  

In my case I sold off appreciated properties in a location I deemed as having limited future upside, and used the proceeds to eliminate all debt on the better located prime properties I wanted to keep long term.

Explain how difficult it will be for them to rent in the future.

The land we are buying also has secondary value to future expats moving there.  

Quote from @Benjamin Finney: I'm curious what real estate investors and private money lenders like myself use to inform their businesses strategy and predict future market conditions.

Given the demographic of unbanked and underbanked population, the demand for cash will not go away in foreseeable future.

I want to be somewhere I will enjoy but also somewhere that’ll be a good investment for either short term rentals or long term rentals in the future. 

Best of luck for your future!