No change fees but you do have to pay the difference in ticket cost, which can be substantial.
Correct BUT fares now are crashing so do the research
I checked some fares and they are NOT crashing from my area.
Fares are always area specific both departure and destination. A friend of mine changed her SXM trip from mid-April to mid-June and the fare was about $120 cheaper (just under $500 n/s...BOS). She is also coming down to Ft. Myers next week on a $33 one way JB fare. Crashing was a bit of a generalized choice of words and doesn't apply to all destinations and time periods