I have noticed that the airline rates go up, after 21 days, or more are between your roundtrip flights. Has any one else noticed this, or am I losing it. I wouldnt think, you would be penalized for staying longer than three weeks, at your arrival point before making a return flight. Iam looking at a 35 day trip to Europe and the fares for round trip are higher than for a 21 day trip.....Whats up??