A thing thats been bugging me is when to trade a tech. I often find myself low on cash in games, and I'm reluctant to lower my techrate, so I often end up trading techs to everybody often for fairly low amounts to keep my teching going. I sell it to everybody that I have contact with in the same round. I hold on to the strategic og wondertechs, but I can't really tell whether to trade for low prices (120 gold maybe) or refuse to trade unless they have a lot more. Problem is, that they don't, not untill very late game. Any pointers on tech trading ? I play nobel/prince for reference.