No, that's not right. I did some tests and I believe that they ask/share an amount that is a fraction, maybe 25% of what one has (AI or player, it doesn't matter). I tried indeed to sell techs to a civ that was ahead in gold and it was giving me much more money than another for the same tech. That would be indeed a good way to know roughly how much gold a civ has and, sure, which techs we have a civ is missing.
About the same should apply to spies when we make them stealing gold. Too bad I never use these strategies. Maybe I would win the games in a much easier and faster way.
