50% cost reduction
40%. Base price is 250 with no planet special abilities.
and a 33% build speed increase on them anyway.
Still, these are instantly (or nearly instantly) added as soon as the planet is colonized, so you don't even need to wait for that one starting LEV to get it's job done.
~~
Sakhari and Vanechka pretty much hit the nail on the head. Having an Akkan in your assault force is very very useful, not only for Ion Bolt (which at 2 or 3 can keep an enemy capship permastunned as long as your Akkan has antimatter remaining - and with upgrades it should regen fast enough) but for Targeting Uplink as well.
Plus Colonize lets you lock down planets as you go when attacking the AI, which has a horrible tendency of slipping colony frigates past you from nowhere, meaning you end up running back and forth playing whackamole.
Just remember not to set Colonise to autofire and you're good to go.
I hadn't thought of that use of Armistice, however.
Ion Bolt is also very nice for keeping an enemy capital ship "locked down" and unable to fire, as well as keeping it from jumping out so your forces can kill it.