The cost of changing a flight can vary depending on the fare class, the timing of the request, and the availability of the new flight. Copa Airlines typically charges a change fee, which can range from 150 to 400 or more you can call on depending on the circumstances. Additionally, passengers may be responsible for any difference in the fare price between the original and the new flight. It's important to note that some fare classes may not allow changes at all, or may have stricter policies regarding the timing of the request. For example, some economy tickets may only be eligible for changes up to 24 hours before the scheduled departure, while more flexible fares may allow changes up to the last minute.