Much more money can be made by a ancient age technology trading strategy. When map making comes around, everybody trades maps for technology, so everyone then is even technologically, so get a lead in troops, map position, and money then. Use minimal (10-20%) science, as long as you're spending 1 gold every turn, you will get an advance in 32 turns. Research the most advanced technology possible, for example if you are industrious research math first, because you're likely to be able to sell it.
After map making, continue to trade technologies until YOU'VE left the ancient age. If you aren't scientific, sell or give all the ancient age techs to the scientific civ that eigther : has the Great Library (he'll get it anyway) or seems the weekest, then buy Monotheism from him. Building Universities, (5) banks & Wall Street will usually cover the cost of troops, even Jaguar Warriors so Feudalism can wait.
After that, the only tech I buy then sell to everyon is Monarchy, it's overpriced, and I love watching 15 civs scramble for 1 wonder, knowing there will be 14 losers.
I do also sell to the backward ones later, especally for luxuries and resources.
As for wonders, when my science city is on the coast, I build Collossus (not much competition early). When I get Mono, I build a palace, which becomes the Sistine Chapel, when I'm reasoably sure of getting it. Then Bach's & The Observatory & Newton's. I skip Sun Tzu's & Leo's (too competitive)
I've won at Monarch, and am winning at Emporer, and have regularly won at Diety in CivII & CTP.
