If you're talking about just straight coin farming, you're likely a lot better off doing a dreamland zone. Cities can be okay, but camps tend to have limited Ja monsters (easiest to proc) and they're usually mixed in with WS/Magic mobs, which are just a pita.
In dreamlands, you can just run around and proc ja only according to time, which is a lot more convenient. (And generally accepted to be the fastest way to farm in Dyna)
If you plan on doing EP mobs, make sure you /search zones first. At times there's some pretty crazy competition at EP camps.