Buyout is a mechanic that I don't think is well implemented, even for the Lumeris who have advantages toward it. I think a lot of its modifiers should be applied on the empire level, not the system level to work better. But hey, I think it will be fun to play on Endless difficulty and get the highest buyout "abuse" going that I can. So any recommendations? I'm thinking:

Faction: Lumeris (although I'm fooling around with some custom faction ideas)

System Improvements: Superspuds (all three tiers). I may restart if Superspuds are not in my starting spawn.

Minor Factions: Looking for Amblyr (assimilation trait) and Eyder (20 population trait) 

Environment (Minor Civilization Quantity): High; so as to have better odds at locating and acquiring Amblyr and Eyder.

Galaxy (Number of Constellations): Unique; so at to explore faster to locate the 2 minor factions.

Galaxy (Size): Large or Huge to spawn the 2 minor factions, but not so large to have difficulty locating them.

Galaxy (Resource Abundance): This is tempting to set to High for plenty of potatoes for three system developments, but I think Lumeris can generate enough on their own with traits. Not sure.

So if I'm not mistaken, the highest buyout reduction you can get is 90%.

(1) Superspuds: 45% (All three system developments)

(2) Worker's Campus: 20% (normally 10% for other factions)

(3) MXBA: 10%

(4) Ambylr: 10% (Industry Contacts assimilation bonus)

(5) Eyder: 25% (20 Pop bonus)

Am I missing any?

Of course inflation is a huge factor in doing all this so being Lumeris will help. There is also the Tier 5 Endless tech, but that is so late that its basically non-existent for this.

Government Type: Republic

Political Party Affiliation: Pacifist and Religious

All buyout (ship and construction) is capped at 95%? What's your read of the Eyder 20 population trait - is it both construction and ship gets 25% discount, just written differently than the others?