I am pretty much done with the core rule section of COLLAPSE: character creation, resolving uncertainty, combat, and damage. I want to add a section on explosives, fire, and damaging terrain (doors, window, etc.) and then its complete. I'd probably add a few potential setting overviews and follow each with a short list of media resources (novels, movies, comics) for further reference.
I am considering releasing these core rules for free, maybe I'll offer them printed as well just to see if anyone wants to buy them. Plus I can practice my bootleg book making skills.
Then I'd charge for the follow on "blue book" reports dealing with specific "administrator eyes only" details around specific scenarios. These would include scenario hooks, details around events like zombies, alien invasion, post nuclear, etc.