Courtesy of the Endless Space Wiki dust buyout cost for formula is



(0.75 * industry_cost_remaining )^1.25 * (1-luxuryBonus) * (1-sum(system_buyout_bonus))





industry_cost_remaining for the item you are attempting to buyout

luxuryBonus : empire buyout bonus granted by Pre-Schism artifacts 0.03, 0.06, 0.09 or 0.42 for 1,2,3 or 4+ copies ...

system_buyout_bonus: 0.2 Abundant Luxuries (improvement) , 0.3 revenue zen (improvement)







X axis is industry cost of the item to rush buy





X axis is remaining industry cost of the item to rush buy

Y axis is dust cost to rush buy per remaining industry cost ratio



Ex.

pay ~4000 dust to rush buy a 1000 industry cost remaining item



As soon as industry cost is above 4.4 [allitemsinthegamecostmorethan4.4industrytobuild] Industry becomes more valuable than dust when building ships//improvements - another reason to focus on industry early instead of dust ...(it becomes increasingly more wasteful to buyout as industry costs go up)





With Pre-Schism artifacts monopoly and Abundant Luxuries and revenue zen built the buyout dust cost/ industry cost becomes







So items with less then 700 industry build cost remaining - will cost less dust than industry to buyout ...And even with the very expensive industry build cost items - dust buyout price is brought down to much more accesible levels...