The random number generator in Final Fantasy VI is totally broken, and sometimes it makes you end up getting the same thing over and over and over again for some reason, even if it's a rare occurance in some cases. I'd say to just keep trying, but if you've actually done anywhere near 50 tries that seems permanent to me. Maybe you somehow made the game stop producing random numbers altogether for the auction house somehow? That sounds annoying. I hope it fixes itself. Have you tried saving, turning your game off, and restarting? If something went to Hell, that might fix it...it's worth a try I guess.