Containers trade is 'static' so when you once know which container major planet buy, you can sell it there all times. You can also see this 'right container' when you look at base details using nav-map. .. and btw is also few small bases 'train' friendly. But it is rly for space exploring and talk in-game. I have bigger experience with train, so if you see 'Forlon' or SA_Trader02 just call for info