AA many years ago quietly removed the REFUNDABLE online radio button and replaced it with FULLY FLEXIBLE online button and yes I have had penalty amounts in the past as high as $600 for a FULLY FLEXIBLE ticket refund.. So be careful or figure out how to read those fare rules. Almost no one but a few people on flyertalk have that skillset to understand the fare rules that are a hidden link on the very last online page . Good luck and be careful or call AA and have them verify and mark up your PNR with notes.