I've finally had a chance to tinker in the diplomacy stuff now, and have noticed that the Empire who you are trading with has all their (gildar, materials, metal, tech) shown as absolute values, that is, the actual amount of the resource (or tech) that they have.

I also noticed that there is a very nice (would be good to get the equation that calculcates) perceived value system.

I suggest that instead of seeing the actual amounts of resources/tech that the oponent has available, show only a perceived value of the total of the resource that is available for trade.  In fact, everything done on the trading screen should be shown as PERCEIVED VALUE, never use absolute values.  This System would serve three purposes:

1) More realistic bartering, when yuo're trading you don't tell the other person "I have exactly this much of this" (absolute), you say "I reckon I could find enough of this to make it worth your while" (perception).

2) ESPECIALLY FOR TECHS, the abuse of the diplo screen to find out what the other team has researched would be impossible if you were only told they had so much perceived value in the techs they have researched that you have not.  Techs probably need to be resolved into actuals before the trade is accepted, however only those techs put on the table should show up.

3) People wouldn't choose not to trade with another empire because they knew they were always getting less absolute in return than what they are paying.

I think at the very least an option shuold be available to toggle "Only perceived values in diplo screen".  What does everyone else think?