Thanks! I'm glad you find it useful. It may sound weird but this is me being lazy. I didn't want to calculate profitability each and every time I decided to trade, so I figured it'd be easier to do this. I added the pseudo-formula above, which is fairly simple as you'll see.
For the sake of precision, there's an implicit assumption that a "Supplies_1 + Look_for_2" profit is equal to two "Supplies_1 <> Supplies_2" or "Looking_for_1 <> Looking_for_2" profits. It might need some weighing to properly adjust it (just a single parameter), but I haven't paid much attention to that proportion yet.
My goal was to find some circular trade route, but I think it may need to be done programmatically. Or maybe with some matrices product... Something I never thought I'd need.
Edit: Actually, I realized it's an ant colony optimization sort of problem, which is solved programmatically.




The opponent's chosen card just stays there. Reloading actually sends me to the previous level as if I'd lost the round (which is why I found it strange that returning to menu didn't do the same).

