Each bedroom has a different bucket assigned to it. Ironically, even though bedroom A is the least desirable and is sold last, it has the highest bucket!
So if you had bedroom E (and was the lowest bucket) and you switched to bedroom A, that means that bedroom E was once again available. Thus the lowest bucket was once again available.
That is not true. There is no specific price assigned to specific rooms. I’m sure the workings of the revenue management system has been explained here before, but basically, bucket availability is based on the number of rooms available. If a fare is available, any room can be sold at that fare, but the agent has to do it correctly.
The standard practice when someone asks for a room is to let the computer grab a room automatically. If a passenger then asks for a specific room, the agent is supposed to release the first room (and thus bring available inventory back to its previous level), the. Grab a specific room. If they don’t do it (and many agents don’t, or aren’t even aware of this process), then when they grab the specific room requested by the passenger, they are grabbing it from a reduced inventory situation (because the first room, auto-assigned by the computer, is already out of inventory).
From what I recall from my occasional dealings with Arrow in my Amtrak days is that fare bucket availability is expressed in terms of percentage of total inventory. So, for example, D might be available until 20% of the inventory is sold, C until 40%, B until 60%, A until 80%, S until 100%. In this hypothetical situation, a train with a single sleeper and no sales would have inventory of DD1, DC2, DB3, DA4, DS5.
Take the first room out of availability (doesn’t matter which room, nor does it matter which fare you decided to use), and availability goes to DD0, DC1, DB2, DA3, DS4. Also note that, while this essentially never happens (nor, realistically, should it), it is possible for the agent to specify a higher fare bucket if it has availability. So, the agent can manually grab any of the available fare buckets. Doing so will *still* reduce availability in the lower fare buckets, because, again, it’s based on the overall booking level of that class of service, not based on a specific allocation of a number of rooms at an individual fare bucket. So, in my hypothetical example, as long as at least one room is taken out of availability. The lowest bucket will be C, regardless of what room or bucket the first sale used.
What also trips up folks on here is (I assume) the notion that these bucket allocations remain static. They are frequently being reviewed by revenue management, in addition to the fluctuations in availability resulting from passengers booking and cancelling. So, when you changed rooms, they probably already either increased the threshold for the lower bucket, or someone cancelled bringing that bucket back into play.
While it’s possible they’ve made changes to the system in recent years, when I was using Arrow, there was no mechanism in place to tie a specific room to a specific fare before it was booked, That was always a myth invented by AU.