I sent to Kuche 50, unlikely that we ever increase this amount.

I don't know, if you understood the plan? The techs from Invention to MT are 7000 beakers. The Küche expects us to supply half of that sum (3500g). Plus we still owe them what is left of their 500g credit, and we still haven't payed our part of the lux deal.
So we are looking at roughly 4000g to be paid over the next 40 turns.
Also it is important that we send them a large part of the gold
in the beginning, so that they can short-rush their libs and do 4-turn research right when they start researching. Otherwise the surprise factor will be lost. (Atm the Küche is a very slow researcher {they are slowing down Chivalry for us, so that we don't have to face Knights too early!}, and Eagles/Anarchos will both expect this to stay that way over the near future. They will never expect the Küche to get Cavs in only 20 turns...)
And: one prerequisite for their generous interest-free credit was, that we grant a similarly generous credit for the MT-plan.
BTW: our GA started in T093, so our last GA-turn will be T112.
My plan was to
- pay the first 1000g until the end of the GA. (Something like 8x140g between T105-112. Ok we have already payed 150g of that sum, so we can now do ~8x110g.)
- Then pay another 1000g until T125 (when they will fire off research), like 13x77g.
- After that they will no longer need our gold, so we just send a bit to cover any deficit, e.g something like 20x25g = 500g between T126-145. (Plus a bit more for our still open debts?!)
- And then we pay the remaining 1000g after we get the techs.
Prerequisites of that plan are that
a) we don't need any of the gold ourselves (We should have rushed everything we need now. Better build markets with the GA-shields and no longer rush units.)
b) we can reduce our unit upkeep (Fill the still missing settlement locations, get all river/lake towns to size 7 asap)
In cases of emergencies we can use our gold for units again, but I would like to do this only if really necessary.