My opinion on every single k unlock except bonus ships (feel free to discuss):
FleetshipsI usually unlock triangle IIs at some point. These are my gold standard for unlocking other stuff. I often unlock mkIIIs of a couple, but I do think k costs for mkIII fleetships needs to come down.
Maybe between 4 and 5 thousand (inc).
In games with scouting, I unlock scouts II always and III never.
StarshipsGenerally, the starships are in a good place now, though I only unlock mkIIIs with a huge empire, including an ACS.
Flagships II-III High on the list.
Alien starships I-III : I really like these. Even though they bankrupt me.
Leeches II-III : when I have spare k, which is almost never.
Raids II-III: Never. 1000-3000 would be reasonable prices, not 4000-4000.
Siege II-III: Rarely. But they have their uses.
Bomber II-III: Often. If a planet has a fort and ion cannon, I turn to these guys.
Cloakers II-III: Usually worth unlocking the mkII. Occasionally the mkIII.
Enclaves: II is a ripoff. III is okay. IV is never worth it. I propose 1000-2000-2000-12000 for enclaves II-III-IV-V (mkIV has the drones, mkV has the mkIV fleetships).
Riots II-III: Awesome.
Scouts: Very occasionally I will unlock mkIV for antimissile capability. Mks II and III don't really seem to have a reason for existing.
EconomyEngi II-IIIs. I unlock IIs almost every game, but can never justify 3000 k for the mkIIIs. Please reduce the price of the mkIIIs to 1000.
Harvesters II-III Often worth unlocking.
Econ stations II-III I can never justify unlocking these. In the games where I have enough space to cram them all in, I want either military stations for my chokepoint or logistics everywhere.
Log II-IIIs:
my precious logistics stations mkI. These are also pretty dusty from their non-use.
Military II-IIIs : Situationally (read: iff massive chokepoint) useful.
I think either removing the cap, lowering the k costs, or both is called for with the basic station unlocks.
Warp Jammers : I unlock these almost every game, though they definitely have suffered with threatfleets, minor faction attacks, etc.
SupportAdvanced Warp Sensor : no complaints at 250 cost.
Transport II: Never worth it. Change price to 1500 or 2000.
MRS: Also never worth it. Change price to 2000.
Exo-shield: Ok at 750. Maybe add an advanced version for 750 more with no efficiency hit.
Spacetime manipulator: What a strange tech. I've never been able to get past its massive energy cost.
Decloaker: Just fine as a situational unlock with cloaked raiding potential.
Normal ffs: In a good spot.
Hardened ffs: Terrible. Their armor rarely translates to more effective hp than their non-hardened counterparts, and they don't unlock modules for other stuff. Halve their k cost or double their hp.
Fortresses: They're fine. K-for-firepower efficient, at the cost of being really expensive and defence-only.
Mod-Fort: Good spot also.
Mini-fort: Good for 1000 k, it protects all planets from tiny incursions, but anything resembling an actual attack has them crying uncle. I would like to see more per-planet defenses added, like a riot fort or bigger mini-forts.
TurretsMost turrets need to come down in price. I can rarely justify unlocking these. These are my proposed prices:
Basic Turrets: Fine.
Spiders : 2500.
Missiles : 2000-3000
MLRS: 1500-2500
Flak: 1000-2000
Lightning: 1000-2000
Laser: 2000-3000
Tractors: 2000-3000
Tachyon: Fine.
Gravity: Fine.
HBC: Fine.
Basically taking more than a system of k (or 1.5 systems if we go with the rescale) is really bad for something that doesn't increase your offensive strength. Drones are nice, but they are a long way from completely addressing the problem (again, partly because the Enclave IV is exorbitant).