Hmm, if I zero the sliders and put all citizens on 2c tiles I can get 12gpt and buy Writing. Okay, do so with Zulu, leaving me 12g and no gpt.
I'm starting to see how to work this I think. Buying BW was a mistake because it's expensive (Colossus not yet built plus a new unit, making it a premium tech), and buying it would only reveal IW, and I knew it was a fair chance that all the other civs might already know it, plus it reveals a resource and has a unit so would be difficult to buy outright, too.
I started to say I goofed trading for Wheel earlier, but I did think there was a fair chance England didn't know it yet, and it would have been good trade fodder (at the time I knew where England was but didn't yet have contact). But getting Wheel without WC didn't reveal any other tradeable techs. However if I bought CB I could broker Myst when it became available.
So, after mortgaging the empire to get Writing, what next? I want IW most of all, but it is the least useful trade. I know nobody has Math, so nobody could have Construction yet (plus it's too doggone expensive for now). However if I get WC then I may get broker options on HBR, and if I get CB I may get broker options on Myst. So even though IW is more valuable as a single tech, I'm better off getting CB and WC first and then seeing if HBR and Myst are out there to work into this trade session.
Trade Writing to England for WC, CB and 19g. (Couldn't afford IW in the same trade. No worries.)
Myst and HBR are both out there, and not all civs have both! Only two civs don't know writing now, China and Arabia. China knows HBR, Myst and IW while Arabia knows HBR and IW. So, Myst first: Writing to China for Myst straight-up because he has no gold. Now I'm up Writing on only Arabia but am up Myst on both Arabia and England. (Quickly check to see if anyone has Poly yet...nope.) Trade Writing to Arabia for HBR and 32g. (Oops, thought I traded him Myst, but I'm still up Myst on him so it must've been Writing.) That goof may have cost me, but I get IW from England for Myst, HBR and 24g.
Now Arabia is down Myst, but the rest of the known world is at tech parity. And I have 34g and no available gpt for 20 turns because of what I now see was a very bad BW buy the last turn.
I have a lux hooked up, am about to found city #3 and am starting to grow the capital, so I think I can manage the large gpt deal, but I'll be off of even min research for at least a few turns. I won't be paying unit support soon, although I do have a granary completing in 5 turns. Still think I can cover it with pop growth and the new city.