Originally Posted by
jbflyboy84
Sorry guys for the spam. Just had another thought. I recall somewhere that if you make your changes in MMB, it will automatically change into the LOWEST available RBD not into the same RBD as booked, is that correct?
If so, I guess I'll make the changes via the CC.
You can't ever get a refund moving to a lower priced RBD so the question I think is moot

The website breaks down the changes into fare differences, taxes and change fee so if there is no difference in fare you know you are in the same fate bucket.