So you say have a choice to either
A) Ovie scout
B) Do an evo chamber scout
Option A)
You make 2 overlords, scout with one lose it, other provides supply
Cost 200 minerals, have your standard 8 supply
Option B)
You make evo in their base, costs 250
You still need an overlord for supply though, so another 100
cost 350 minerals total
I really don't understand where you are coming from. Yes if you make 2 overlords and lose one you are up 8 supply that is true. If you are planning on losing an overlord scouting you typically make an extra one, this is where you pay the "cost" of the overlord and it is 100 minerals. This is similar to paying for the hatch cancel into evo chamber which is 250 minerals.
You can make the new overlord so that it pops before the old one dies preventing any supply block from occurring. If you also require an additional overlord to provide extra supply you can make that as well.
Actually tbh, you got the maths wrong there. If you're looking at minerals lost, its 100 to 200, not 100 to 250. Minerals spent is 200 to 250, if you replace the overlord for the scout and the drone for the evo chamber. If you look at the overlord option, you have 8 supply left to fill if you havent been making units at all.
Either way, its pretty close, and you can dispute 50 minerals or 100 minerals difference is made up for in the fact that the evo chamber gives better scouting and also a few different options.
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