Originally Posted by TheBOSman

I've seen AA instant upgrade fares that allowed for this before. In case of IRROPS, you would not be guaranteed accommodation on another flight in the first class cabin, or even the business class cabin, since you have purchased an economy fare with an instant upgrade into first class. While not as common for economy to first when business is offered, these instant upgrade fares are extremely common for Y-J, J-F, or USA domestic Y-USA domestic F.



There are numerous cases of fares being available only on the carrier's website. Admittedly, this is more common with carriers like CX than with AA.



Simple: Many corporate travel policies don't allow for First Class purchases, even if it is cheaper than Business Class (as an example, my current employer is economy only on all flights for employer-sponsored travel, even if F or J was less it is not allowed). Thus, as counter-intuitive as it sounds, it can make sense for the airline to price F below J, as demand for J is much higher due to the restrictions of corporate travel policies. This is the same reason BOS-DFW-AUS can be cheaper than BOS-DFW: airline pricing has absolutely nothing to do with the costs of providing the service, and everything to do with the demand for the service in question. Nobody would say BOS-DFW-AUS being cheaper than BOS-DFW is a mistake, would they?