Run some test itineraries to compare the various sites. Here is what came up
( I didn't mess with sidestep. I downloaded it once and it was so irritating. I visit a lot of travel sites and it kept popping up all the time, so I deleted it.)
PIT - MCO (7/1/01 - 7/8/01)
Best fares:
Orbitz : Airtran $206.50
Qixo : Airtran $236.50 + $10 Qixo charge = $246.50
Travelocity: Airtran $236.50
Expedia : US Airways $252.00
Hotwire : Unknown Airline/flight time $ 252.00
Airoutlet : Northwest $195.00
Airtran website : Airtran $191.50
CMH -TPA (6/1/01 - 6/8/01)
Orbitz : Delta/Continental/Southwest $207.50
Qixo : Delta/Midway/Southwest $207.50 + $10 Qixo
Travelocity: Delta/Midway $207.50
Expedia : Delta/Midway $207.50
Hotwire : Unknown Airline/flight time $164.00
Southwest website: Southwest $207.50
Delta website : Delta $207.50
Airoutlet : Northwest $158.00
What does this little research project prove. No one site is always the lowest. Usually, they are all the same. Always check the website of the individual airlines.