Something most passengers fail to understand is that a ticket is a de facto contract between the airline and the passenger to transport you from point A to point B at a certain date and time . If a passenger wants to change flights that is essentially a breaking of the contract . If you had a contract with a company and just decided to change it , you would be considered to be breaking the contract and liable for damages etc. Changing your flight is basically contract renegotiation for a fee. The airline is changing your contract for a $50.00 or 150.00 fee depending on conditions. What would something like that cost in the legal field? Read the terms of transportation carefully. It spells it all out.