When i first began the game i did not understand it, but after playing it a few times i understood what to do, clearer instructions (the way it was written i kind of just skipped past it) and an undo button 4/5 :D
The guy who sells him all of this stuff used to be an investor, so he know that this whole "Zombie Outbreak" is just something that will fade over time, like silly bands, and hippies, so he is making the best of it, and scamming about a million dollars from some random guy trying to get to a helicopter he could probably just walk to.