My original routing was ORD-MAD-PRG-MAD-VCE-MAD-FCO-AMM-JFK-SEA, taxes & fees were quoted $279.xx Then I changed the routing to SEA-ORD-MAD-PRG-MAD-VCE-MAD-FCO-AMM-ORD. When I called to ticket it, the taxes and fees were increased to $354.xx How could such a change increase the taxes and fees for nearly $80? Basically I substituted the JFK-SEA with SEA-ORD, and changed the AMM-JFK to AMM-ORD. I checked the taxes and fees for these flights SEA-ORD,AMM-ORD, then compared it to AMM-JFK-SEA, I didn't see significant change. The AA agent did sound extremely unprofessional. She couldn't even find the fees at first, then when asked about the miles needed, she gave me the wrong amount of miles (higher than the correct amount obviously). I then asked her to double check with rate desk, she told me the rate desk is closed for today. Then put me on hold for 20min, and came back with the same answer.