[Prophesy]

Humanity cost is the same,
whether its .65, .45, whatever,
the humanity cost with each type of borg remains the same,
whether upgraded once, or maxed,
(to clarify, a .45 cost borg will take .45 per upgrade level)
but the cost will never increase over base,

however,
the cost in money will increase quite a bit,

for example,
I have 2 levels in one of the top-tier borgs,

currently,
to increase it to lvl 3 would cost 1,050,000$,

money gets high,
but the humanity saved is priceless