I have to fly to Guatemala City from New York City on January 13, 2010 (or thereabouts). I believe I have to return at the end of April (about 4/22), but I'm not certain. Right now, the best thing to do looks to be buying a one-way ticket on Spirit (125 plus fees) down, and then hoping that the 187 dollar Spirit flight for most days in late April does not change and become more expensive by March.

If I decide not to go the "one-way," "one-way" route, I am forced to buy a Continental round-trip ticket for about 310 dollars, which I assume would have a whopping change fee for international travel.

So, my dilemma: Do I gamble with Spirit and hope that a future one-way ticket is affordable? Or, do I just purchase the round-trip ticket on Continental and then deal with change fees if need be? Considering this complicated scenario, do any of you have any tips that you would kindly share? Do you think I could find a sub-200 dollar fare (one-way) back from Guatemala City to NYC if purchasing over a month in advance? Thanks so much!

It sounds like you're fairly certain your return date will change. If so, I would go for the one way, and once you know your return date, look at another one way (back) or even a r/t that could be less expensive. If OTOH you had a return date locked in, the r/t ticket seems to be a better option.

Double check that Guatemala will let you into the country without a confirmed ticket out. Some countries require you to have proof you are leaving their country before they let you in.

Then you just have to make a refundable flight reservation, or show proof that you have a coach to a neighbouring country reserved.