possibilities.
1. somehow the route has no competition and was created during a brief bug stint where it was calculated as if it had less frequency then it really did.
2. you've changed alliances, your alliance structure has changed
3. the airports themselves have shrunk in some significant manner (airports have an innate hub effect. i still need to implement any given airlines individual hub effect however).
4. if it's not the exact same plane, yes the price will be different. from the sounds of it however it is.
5. i've made minor tweaks along the way to the calculations, they shouldn't be significant however. maybe 2-3% difference from this. most of it is washed out by #2 and #3
6. you're creating the new route, then closing the old route adding in the effect of your self-competition
7. There have been relatively significant modifications to the self-competition penalty throughout the age, mayhap it was calculated originally under (again, on old unchanged routes) the weaker modifications.
and unfortunately there's... 8. there's some bug hiding i haven't noticed or found yet. no guarantees it exists, but. just saying it's possible. :oops: