Is that 852 coupons or 85k cooupons? thats the coupons number according to which shop?

Btw. how much gold is this gonna cost?

considering cultivation becomes so expensive in the later stages, what's the optimal stage we should cultivate to if we're focusing on just 1 summon?

i want to increase my summon's chase dmg by as much as possible (which is done by advancing to the next stage, right?), but at what point should i move on and cultivate the rest of my summons for the power?

it's 852k haha :D

It's according to the normal shop , and well generally that's also mostly the cost of unbound runes in events

But something that's not too expensive but still good for stats I'd say finishing 3rd hexagon for blue summons, 5th hexagon for purple summons and finishing 6th hexagons for gold summons

Not easy but I'd say that's a goal you should aim for, about optimal costs just look at their prices and see in which order you should make those goals