Unfortunately, since Blizzard doesn't make the BMAH accessible through the same API as the regular Auction Houses, you are expected to log in and travel to the Veiled Stair in order to see whether there was anything there for you.
It's an extremely effective gold sink, but it's tucked away in the middle of nowhere, and you can't see what's for sale on your realm from the remote AH. The Black Market Auction House is a special AH that allows you to buy items that are rare and sometimes unobtainable with gold otherwise.
