Ok, I'm still playing my first Regent game on a Huge map with 13 other civs. According to some strategy tips discussed previously in these forums, I started to sell every tech to every civ I had contact with already from the ancient times. Now I'm in Modern Ages already and NEVER have had a tax rate higher than 10 percent... I've managed to sell Superconductor to 2 civs for 130 gold per turn, so my turn income from other civs is approximately 2000 gold per turn and I'm bying a lot of improvements (actually, I already have bought them all and now I'm trying to accumulate an enormous cash for war purposes). Everytime a civ has developed a tech I don't have, I buy it from them for almost every price they demand (up to even 4000 gold as a lump sum) and then sell it again at once to other civs for prices that in total usually exceed the initial one. The only tech I didn't sell at once so far was Synthetic Fibers so that I could form a reasonable force of Modern Armors before AI's civs. But as soon as I discovered that Persians also have developed that tech, I again sold it to all other civs and made a solid profit. As soon as the complete research will be completed I'm planning to take some steps towards the conquest victory... and hope that some 60 Modern Armors will be a reasonable argument in favor on these intentions...