Been trying to figure out the exploration cost formula. So far I got this :
exploration cost for 1 acre
Y = (ln(x) / ln(2)) * X + (0,0000282 * X^2) + (2,683 * X) - 1269
X is current landsize (including incoming land)
Y is gold exploration cost
So far I've seen, the maximum inaccuracy of this formula, is 3 gold
The formula has been derived from data from 350-5000 land
Ofcourse, Leshkins need to multiply with their military modifier.