Retainer question

[Erendis]

You can see all 4 markets regardless of which city you are currently in. The only thing about them is you will be charged tax if you buy something that isn't sold within the current city you are in. (For example, buying Gridania Market stuffs from Limsa Lominsa)

Also, sometimes tax is reduced for the goods you sell in some cities.

On the same topic, is the ONLY reason you send em out on Ventures to level up so that one can get some stuff unavailable anywhere else at 50ish? Tough game there, I tried a Quick Exploration and got a ton of XP, but on the next one, less XP than the regular hunting mission.

Quick venture exp depends on the item it brings, which is completely random. If you want your retainer to level up faster the best is to use normal gathering ventures while you are online and 18 h ones when you won't be online for a while.