Yes, the Pass is the only special key item that you can buy or sell. I was hoping for more than a dance there....
You get an augment in the dressing room that doubles the gil you get from battle in the DS version.
The After Years mixed it up a bit, it's a little more amusing:
[spoiler]Evidently, the original dancers are still employed, since a bunch of old women run out and steal Palom. The screen then blanks out, which is slightly disturbing. Afterward, you can go into the dressing room and buy a Member's Card, which lets you go down another level. In there, you get normal dancers, who force Leonora to dance with them. You can buy a whole set of status blocking (but awful stats) Queen's equipment for Leonora in here, and a VIP Card, which costs you all of your money (you're capped at 99999 in the tales). This gets you into the bottom level, where the dancers spell out Palom's name. After that, you get a black tail as your reward for wasting so much gil.[/spoiler]