I try to monoplise the trade goods as soon as i can, and i dont sell them, least not for a LONG while, late game if i have long term allies and i running on hard times, then and ONLY then i might part with the trade goods.
In my last game i managed to get all the trade goods to myself heehee
I kind of hope they can introduce MORE trade good to game, so its not so easy to molopolise them all, but also t create more veraity, even if some other good was very simlar to what already in game.
I would also like to be able to see at a glance which people OWN the trade good, and which people are benfitimg from it