Thank you
Thank you, both. Since the thread was posted, I have found the answer to my question. Well, not exactly. I changed my mind about returning to DR from GUA, instead of the US. (Long Story) Nevertheless, I found a website, the name I cannot remember right now, which offers student discounts on airline ticket. I believe my flight to GUA from JFK, round trip, with the student discount, would cost less than 7 hundred dollar.
Thank you, again. I always appreciate other's advice.