The option to disable technology trading is a "kludge", a stop-gap measure to solve a problem that we all acknowledge undermines game challenge. In the last patch, the AI started charging more for some weapons technologies, and this definitely feels like a step in the right direction. I would like to propose the following additions to the AI in order to solve the technology trading issue, which I think is consistent with how Stardock would like to challenge players:
1. The player (and AI) races should have a counter that tracks the average number of times it sells any given technology it obtains.
2. When an AI sells a technology to the player (or another AI), it should charge a multiple of the base value of the technology based on the value of the counter. Thus, if a buyer race usually sells technologies to 3 other races, the seller race will charge 4x (400%) of the value of the technology. In this way, profit on technology trading will no longer be a landslide, but will instead be determined by small differences in Diplomacy skill.
3. Some AI players (certainly the Terrans, possibly others with strong Diplomacy) should evaluate whether they can make profit buying and re-selling other races (or just their own!) technologies. If they can buy and re-sell a technology for profit on any given turn, they will buy and re-sell every technology that would be profitable to them.
4. When the AI offers a technology trade with another player, it should balance out the value of the trade in BC, either asking for BC from the target race or offering extra BC itself. The AI often offers to trade technologies of greater value for technologies of lesser value, which it should not.
5. Technologies with Galactic Achievements or Trade Goods tied to them should not be traded by most AIs until that AI has built the Achievement or the Trade Good.
There are more steps to be taken which could hone AI technology exchange further, but I think the initial steps of charging more to players who rapidly re-sell technology, and creating AI players who competitively employ the same tactic will make the AI players competitive, and remove the need for anyone to disable the technology trading feature. Other ideas:
6. If the player regularly trades technology to an AI that the AI is hostile to, the AI might issue a warning not to do so any longer the first time, and refuse to trade with the player on subsequent occasions.
7. If the AI has a strongly positive cash flow (i.e. doesn't really need the BC), it might decide not to trade any technology which it is the sole possessor of.
8. Aside from very basic technologies, or once the AI has a stable cash flow, the AI might decide not to trade with races of a different ethical alignment, or who aren't allies.