Supporting economy with high spend rates...

Keep the amount of infrastructure you build only to what you need. Saves cash.

Build production bonus starbases, this helps increase production and lower costs.

Yeah, I suppose if you have like no social improvements and focus only on military you could probably have higher limits.

~SDC~

I just go sell a few tech to random minor race, whenever I'm running short on money. Worked for me so far, though I'm only up to normal AI level...

But then, I am selective on what improvements to build, and prioritize getting trade up and running.

I think it's really vital, if you want to maintain high spend rates and get the most out of your economy, to understand what the buildings do, how much they cost, and use all four governors aggressively.

Even so, it's possible to get there without doing so.

~SDC~

And don't forget to max out your trade. Build starbases with trading improvements along all your trade routes. I usually have all or most of my trade routes going to a minor civ(since they almost always beef up the economy of the planet they have) and then scatter a lot of SB's along it...

I find that the AI is willing to trade certain techs for a lot of money too, especially the trade ones, such as advanced trade and culteral trade, i normally get at least 50/20 for these, sometimes a bit more, trading advanced trade to 5 Major Civs, and 2 minor nets me 350/20. So i can easily maintain 100% spending earlier, i make sure to research another trade tech, and many of the trade goods. When i have one turn left, ill sell another trade tech for 350/20.

After that i will sell something like frictionless clothing to them, i can often get 100/20 for these, and so only have to sel to 3 major civs to maintain my spending, once that runs out i sell to the other 3.

Once thats done im normally pumping out battle ships, and have another trade tech to sell to them.

~SDC~

Always trade off trade techs, if not the other diplomacy techs. You'll get money for giving them more trade routes, and they'll often use some of them to trade with you. It *more* than pays for itself.

I do tend to give "Universal Translator" to anyone I want to be friendly with, but only after I've already built diplomatic translators.

~SDC~

Even if they don't trade with you, it means that they have more money with which to buy other stuff from you. I never hold back techs that increase trade routes. I've been known to let them go for as little as 58 influence points, if the race is out of money.

Right - I don't trade the influence techs for nothing, unless I'm wooing a race for alliance. Money, influence, other techs...whatever.

~SDC~