First off by May 1st or so I have all the trades in place i need. As China its all about being quick if I want war on July 1st. So I stockpile, I dont worry about getting the best prices (that takes too long and sometimes you cant get as much as you want). I also before I go to war cancel all my trades, thus saving my convoys and I have all the resources i need to last years (including rares). And as I stated I am usually buying PLs from Japan much earlier then from the US do to the elements i mentioned above and thus can actually use them much earlier. Its not a matter of which are better (although early on the US items arent the greatest) its how soon I can use them.
I sell lots of supplies, usually 100-120, probably 1/3 of my IC. I dont worry about it, as i have enough troops to either stop Japan from invading or to start the invasion of Manchukuo. I need to sell that many supplies to load up on resources so i can cancel my trades before war and save my convoys (too expensive to try and keep building convoys to maintain the trades).
I sell lots of supplies, usually 100-120, probably 1/3 of my IC. I dont worry about it, as i have enough troops to either stop Japan from invading or to start the invasion of Manchukuo. I need to sell that many supplies to load up on resources so i can cancel my trades before war and save my convoys (too expensive to try and keep building convoys to maintain the trades).