Please do not decide on a coastal city in Chile for retirement without checking out Coquimbo/La Serena. These adjacent cities are a popular beach resort for Chileans and visitors. They are the gateway to the beautiful Elqui Valley, which is quite qn attraction in itself, especially if you like star-gazing. It's really dark there at night!
Make sure about the quality of air,elevation,is not as cheap as other south american countries,like colombia,check out healthcare,visa and resident requirements.Peru fairly easy to and not many assets required.Very stable politically compared to others,higher GDP than all of them,probably more expensive to live then all of them.Rent first.Check out various locations,and sections of the city..Spend or already have spent substantial time in the location,not just making judgements from vacations..Check out neighborhood at all times of day and night.Use native speakers if not fluent in language,for leases,banking etc.