We know that from the general lack of information that we have on pricing and sales. We have trend data that can give us the best days of the week to fly for better prices, and even sometimes the best days of the week to BUY our tickets, but did you know that WHERE you SAY you're buying your tickets can actually affect the price you pay?
I KNOW. MIND BLOWING but true!
If you buy domestic flights occurring in a different country (read: the flights will occur in a different country than the one you are currently in while searching) it is often WAY cheaper if you can convince the airline or website that you are in the "different" country buying your ticket.
Example: If I'm in the US but I want to buy a ticket from Lima to Cusco (this actually happened). I search when I'm in the US, the prices come back around $250-$300 each and I say "no way" and I decide not to buy tickets ahead of time. When I GET to Peru, my friend tells me the direct website of LCPeru (a Peruvian airline that flies between Lima and Cusco), and since I'm IN Peru, it recognizes Peru as the point of transaction and my plane tickets are miraculously over $100 cheaper for each one.
Now, take my personal experience and add this newfound info: you can get the SAME miraculous price drop that I got when I was in Peru by telling the website you are searching while in the US that you are in Peru already, even if you're not. Do the search in Peruvian currency (soles, in case you're interested) and voilá miracle price-drop without ever having reached Peru (If only I'd known BEFORE actually getting there).
It can save you a boatload just to change the point of transaction, maybe pay in a foreign currency on your credit card (bonus if it doesn't charge foreign transaction fees) and do a little extra searching.
This works for international flights, too, but it's a bit more tricky because you'll have to seek out one of many countries in the world that you could have as your transaction point to get the best price (hint to save you a search: it's probably NOT going to be the US...unless a US city is the destination or departure point).
You can see more examples and get more info. by clicking here.
Happy travels!