Exit and entry
In this age of travel as tourists visiting South America we need to look "sharp" departing the US, rich when we arrive at our destination and dirty and poor as all hell once we've finally checked into our hotel and find ourselves (gasp) walking around on the street.
We need to look like we have a purpose checking in so the ticket agent in Hartford won't ask us for proof of "onward travel"; we need to look like we have a wallet full of $100 bills so the immigration officials in Lima won't ask us for proof of "sufficient funds." Then by the time we've collected our luggage it better be dirty and stained and fraying at the edges so we won't get robbed for being fancy foreigners - but not before we exit through customs!
When you travel as a tourist with a one-way ticket to South America you're transported to the land of vague rules, travel myths and horror stories without guidance. The country you're traveling to is all, "Come in, come in… Buy buy buy." The second you overstay your welcome though they're liable to deport you. However, many South American countries give Americans ample time to extend the default 90 day tourist visa.
The airlines, on the other hand, are just covering their asses because if you drop the ball and find yourself in a deportation scenario the airline is liable for up to $1000 per person and required to foot the bill for your return ticket.
Yet still the requirements proving "onward travel" as as vague as ever. In the forums I've read, even travelers going to the same country have had experiences as different as some being prevented from boarding the plane in their home country while others have traveled there 10 times without a single skeptical eyebrow raised.
What it always comes down to with borders and immigration and airlines is people and luck. Neither make travel any easier to predict. Do you get the pleasant ticket agent who's all smiles and "Safe travels!" or the woman drumming her 2" long manicured nails on the counter demanding you buy a $1,000 return ticket promptly or she will not print your ticket? Are you in line for the immigration official who gruffly stamps your passport and calls, "Next!" without even giving you a once-over or the sour man who glowers at you as you timidly pull every credit card out of your wallet until he's seen sufficient proof your funds? Who knows. Does it depend on where you're from? I'm sure. Can we predict what will happen? Hell no.
So what to do? Peru doesn't technically require proof of onward travel, but that is also up to the interpretation of American Airlines. We are not going to be abusing our stay in Peru but we don't want to nail down our future plans until after we've arrived. What's a traveler to do?