You can sell stuff to Sassan in the master's chambers in the battle tower.
If you fly out over the water from the start of the fjords, you should see a bunker high in the mountains behind some anti-dragon shields and defenses. That is where you need to get to lower the barrier and disable the shields (a couple traders in there, as well, after they surrender).
You can either use a teleporter to get up there (IIRC it may be on a high cliff nearby just across the water from the bunker), or I think you can find a spot above the anti-dragon shield where you can transform and drop down.
The teleporter pads in the fjords are either fixed, or have a couple of options for their destination (which you set from a control panel, usually right next to the teleporter). There are also a couple of the regular teleporter shrines in the fjords, which have the full list of available shrines.
