I started 1.0 in Limsa so I've always been interested in the closed buildings/services. As well as the MSK guild, there was also an auction house (not the old market wards, this was something different) beside the ferry terminal in Lower Limsan Docks.
I know people call the market an auction house but I was always hoping they'd turn that docks auction house into a real auction house, like from FF9, where you could bid on rare items NPC's put up for sale or even bid on items being sold by other players. Unfortunately, Bahamut blew that place to Kingdom come a while ago so those hopes were dashed
There are a lot of interesting looking places around if ya just take the time to look around and smell the flowers. So many think that all that exists in this game is dungeons, FATE's and gil. Lots of interesting things outside of those rote repetitions.