Under the $30 package there is flashing text saying that 2 people can share the improved package for $20 each, but how do I use that deal?
Sorry if the wording is unclear, but it says "find two friends" to share the Improved Tier, which comes with three copies, meaning you + 2 friends ;)
In case you didn't see someone has already taken you up on that third copy (https://www.reddit.com/r/Games/comments/3erwxo/cogmind_is_a_scifi_roguelike_about_building/ctigfpg). It's very easy to resell a third/extra key to someone on the net via PayPal or Steam credit etc. Plenty of people have been doing it.
(I'm assuming you're /u/kleep, if that's not the case let me know =p)
How would payment work?
One person buys the Improved Tier and gets two extra links to send to the other two people, after receiving payment from those persons via whatever means is decided between yourselves (most use PayPal, Steam credit, or in some case I've heard of trading an extra key for a Steam game).
Perhaps the key point to get across: It's a social deal, not an officially orchestrated one; identical to splitting a 4-pack of a co-op game bought on Steam with a couple mates.