Bolivia may not immediately seem like an option, but this landlocked country has lots to offer. It has one of the lowest costs of living in the entire world. A couple in retirement can lead a comfortable life in Bolivia for $1000 only.
A significant reason, why this is the case, lies in the fact that it is a developing country. Do not allow this to dissuade you because you can revel in the country history, commerce, and quaintness.
It is a surprisingly elegant and sophisticated place with several trendy cafes, fancy malls, and amenities. Flights within the country cost under $50, so you can travel as freely as you wish.