Some thoughts/comments I have about the trade screen.
- What an AI is willing to pay for a tech you're selling seems to vary not just with the tech itself and your/their diplomacy levels, but also I suspect with the amount of cash the AI has available, and possibly some race-specific preferences.
So the AI might be willing to pay 300bc for some juicy tech if it has lots of cash, but often it seems that it caps what it's willing to spend on any particular tech deal to maybe about 30-40% of its total cash reserve, even if that dramatically undervalues what the tech is worth. In other words, good luck getting 300bc for some nice expensive tech from an AI that only has 350bc.
If you want to sell the tech anyway (see below for a good reason), you can obviously work around their cash limitation by trading a tech from them, but if you're like me, they rarely have much to trade you don't already have.
But you can get extra value from the AI by throwing in one or two of their scouts (or maybe fighters) as part of the deal. Why get their scouts? Well, IMHO, getting 120bc and a scout is a better deal than 135 bc and no scout. You can use the scout to explore, block transports to a planet, or be a quick upgrade away from being a fighter at some later point. Or just sell it for 12bc. But there is the added benefit that it forces the AI to build a new 75bc scout(s) to replace the one(s) it just gave you. In the early game, time and money the AI spends building scouts is not being spent exploring or more importantly building colony ships.
You can also throw in a request for some influence points. Sometimes they won't trade any or just 1, but sometimes you can get thousands from them. Influence points aren't worth very much, but remember that every point you get is one they lose, so it's a double effect in terms of the point swing. It can add up over time if you're getting points from every race on most trades.
- It seems when you stack techs together to trade, their value to the AI decreases for some reason. So you seem to generally get more cash if you sell two techs separately than you will if you sell them both in one trade. I'm not sure if that works in your favor if you try buying multiple techs from the AI (definitely worth trying).
- Minor exploit: I've noticed that the AI seems equally willing to trade for a tech it is about to complete research on as one it is nowhere near. So (using espionage) you can wait until the AI has spent many weeks researching some tech down to the final week, and then swoop in and trade it to them for full value. This lets you get paid for the tech while not giving them any tech advancement they wouldn't already have made anyway. It's exploiting an AI weakness, but I find it so delicious it's hard to resist.
- It seems that the AI is currently unwilling to *ever* trade a mining colony (at least in Beta 4B). I just offered the last place AI 80000bc for one, plus nearly all my techs and some planets, and it refused to budge. I understand that it should rate them highly, but that's just insane.
- If you're the top military power, the AI won't usually trade weapons techs with you at your request, but I just had an AI pop up and make *me* an trade offer on a tech it had just refused to sell me.
- Sometimes the AI is more willing to sell weapon techs to you if you have a military tech to trade in return. I've found it's nice to have a few cheapie defense or low level weapon techs available for this purpose.
- The AI seems to refuse to sell its flagship at any price. This seems unreasonable when it's willing to set a price on whole colonies. I think it should just set a high price on the flagship to make sure it gets good value.
I'm curious what other people have noted about AI trading.
