So many things come into play here, it's hard to answer based on the information provided. However, it looks like the fare was incorrectly calculated (which they often times have to manually do on an international ticket). Adding up all the fares from origin to end on the new ticket, I come up with 964.14, not 1162.87 as is shown in the fare calc line. The taxes appear to be the same, so I'm showing the fare diff of $198.73 plus the $250 change fee. I would call back, insist they go through the fare calc line and do the addition again.