> You can travel through South American for a couple grand a month

You are talking pesos, right? I've been doing this for 2 years now and the most expensive places in South America where French Guyana (about USD 2k/mo), Guyana and Uruguay (USD 1.5k/mo in each place) - both times in rented houses and with all food and transportation included. In all other countries you can stay in regular hotels without any discount for long term stays, eat out every day and still live on less than USD 1k/mo (I did this in Suriname, Colombia, Peru, Paraguay and Brazil).

The trick is simply not to use AirBnB or any other booking site except for the first one or two days in a new location and to buy flight tickets with cash at the airport. Having a clue about local economics also helps to evaluate offers and haggle them down from "clueless gringo" rate to "not so clueless gringo rate" (which is usually less than half of what one is asked for initially).

Are you saying that buying the flight tickets at the airport is cheaper than... say, buying two months in advance?

Just being curious, because the usual advice is to buy a couple of months in advance to find better deals.

You of course can still make a better deal with promotions, but slow travel and "buying two months in advance" don't mix well since it takes away the liberty to spontaneously change destinations or to leave a place if one does not like it (or to extend a stay).

But when one wants to fly next day in South America, in my experience the cheapest is to just buy at the airport, followed by online booking at the Spanish airline site, followed by the English site.