In Gridania, Near the Humblehearth section there is two NM Sirocco ( 200 seal item) and Phlia ( 2 250 seal items). When ever you get a duplicate, that goes in your inventory.. you can still warp to your nation and your item will still be there ( I was surprised by this.. though it would go away). Go to your GC Put in your Duplicate Item for seals, then take out you other duplicate item from loot list, into your inventory , then sell them off for seals as well.

I'm on a 3/4 Item Pace each round being worth (700-950 seals) If you not having luck getting into Toto-rak or DH.. this is the best Optional and Optimal way to go, at least for me its working. Thought I spread the Knowledge!