The best place to buy cheap international plane tickets is online. We've tried travel agencies and they can't compete with the discount ticket websites. You can search google ("cheap airfare South America", for example), or go straight to one of the well-known sites, like Expedia, Travelocity, Cheap Tickets, Hotwire or Priceline.
I just did a quick search for the cheapest airfare from Tucson, Arizona, to Buenos Aires, Argentina, using the five sites mentioned. They ranged from $1221 down to $873, and there were fares as high as $3728. Hotwire happened to have the cheapest, but they were the worst of the five when I searched for a domestic flight earlier. You cannot say which service will find the cheapest international plane tickets from week to week. My number one money-saving tip is to always check several websites when shopping for inexpensive flights.
Before going to Ecuador, I searched several websites that deal in cheap international plane tickets. The cheapest airfare from Traverse City, Michigan to Quito, was $1720. Out of curiosity, I checked Miami to Quito, and it was only $400. Airfare from Traverse City to Miami was $300. Book two separate flights and save more than $1000! The discount sites aren't set up to check in this way (yet), so you have to do this on your own.
If your first flight is late and you miss the second, you may not get a refund, but it is still cheaper (every time I checked) to just book a flight to Miami and catch a flight to Quito without a reservation, thus avoiding this problem. This strategy is best for those in towns without international airports. If you live in Miami, you already have cheap international airfare.
As an air courier, you can get really cheap international plane tickets. Courier companies ship material in the luggage space of an aircraft passenger because it can be quicker, cheaper, and more reliable than sending the shipment unaccompanied, since checked luggage bypasses many of the typical customs delays. The courier company begins by purchasing airfare, and then they resell the plane tickets to you. In exchange for your luggage space, they give you a discount on the airfare.
I saved over $150 on my plane tickets this way when I went to Ecuador the first time. I had to walk several suitcases of car parts through customs, but there was a representative of the courier company on either end, and I did get to look inside the luggage, so I knew what I was carrying. I had to carry a plane propeller on the return trip, but it wasn't too much trouble, and made a good story.
You generally can only be an air courier if you travel alone. Once in a while, a courier company will have opportunities for flights on or near the same date. Otherwise, your travel partner can pay full fare on the same flight. You also can usually only bring carry-on luggage, since the point is for the shipping company to use your checked luggage allowance.
Sometimes air couriers fly internationally for free, and almost always very cheap. It is a matter of how badly the company needs you and how flexible you can be (can you fly to Paris on Friday?). In general air courier opportunities are becoming rarer, due to the recent heavier regulation of international flights. There still are opportunities for cheap tickets, though. You can find out more at The Air Courier Association Website (www.aircourier.org). The ACA can also help you get really cheap plane tickets by way of airline ticket wholesalers, discounters, last minute specials, and stand-by travel.
When searching for fares using the discount websites, try several different departure and return dates if you can. The difference of a day or two can save you a lot. There is little logic to airfare pricing, so don't try too hard to figure it out. Just be aware that if you leave on Friday instead of Wednesday (or vice-versa), you may save $100.
Check the boxes that say "any time" for departure and "2 or more connecting flights". Even if you aren't sure that you want to leave at midnight, see what your options are-the savings might change your mind. Whenever the search criteria allow you choices, take the ones that are the least restrictive for the airlines. Again, if the savings aren't enough, you can always book first class, direct flights, or whatever you prefer.
Buying your plane tickets at least a week in advance is usually cheaper. Also, there can be a dramatic difference (but not always) if your trip is over thirty days. You may want to cut it from 32 days to 30 to save hundreds of dollars on your fare. Play with the dates on one of the websites mentioned. You never know what you might discover.
You can take a bus to a major city, if you don't live in one, and then take an international flight from there to save quite a bit of money. My wife and I recently went to Ecuador for six weeks. The cheapest discount website plane tickets we could find were $3400 for the two of us. By taking a bus to Miami ($352 round-trip for 2), then flying from there to Quito ($622 round-trip for 2), we saved over $2400 - even after the taxi fare from the bus station to the airport. That's a lot of money to us, certainly worth an extra day-and-a-half on a bus. (The whole six weeks cost less than $2500.)
The bottom line is that if you spend a few minutes or an hour to do some research, you might save hundreds of dollars. Good luck and happy travels.
Steve Gillman first hit the road on his own when he was sixteen, and traveled alone across the United States and Mexico at 17. Now 40, he continues to travel with his wife Ana, who he met in Ecuador. His website, Everything About Travel has many of his travel stories, plus tips and information on travel in the U.S. and other countries. Going on a volcano tour and camping at Walmart are some of the more unique experiences documented.