Here are 2 that I found if we want to get gunpowder and astronomy. Just to note, it's 28-38gpt for 1 tech alone! We're essentiall getting 1/2 off by selling a tech that everyone might have 1 turn from now, and getting 2 for the price of 1 in the process.
Iroquois: Astro + Gunpowder for: Banking, 36gpt, 283 gold (of course, the gold/gpt can be adjusted.
Zulus: Astro + Gunpowder for: Banking, Furs, wm, 27gpt, 435g upfront
or: We can do a 1-for-1 deal with each civ (which seems to be the safer bet - we don't lose as much in the process,
Iroquois:
We give banking in exchange for 2g, and either Astronomy or Gunpowder. (I recommend Astronomy from the Iroquois).
Zulus:
We give banking in exchange for Gunpowder.
They will not give us Astronomy as easily.
Iroquois: Astro + Gunpowder for: Banking, 36gpt, 283 gold (of course, the gold/gpt can be adjusted.
Zulus: Astro + Gunpowder for: Banking, Furs, wm, 27gpt, 435g upfront
or: We can do a 1-for-1 deal with each civ (which seems to be the safer bet - we don't lose as much in the process,
Iroquois:
We give banking in exchange for 2g, and either Astronomy or Gunpowder. (I recommend Astronomy from the Iroquois).
Zulus:
We give banking in exchange for Gunpowder.
They will not give us Astronomy as easily.