I think i found a big bug. On each business, it says $ per sec. The fact is, the real value is not $ per sec, but $ per tick, which means the more expensive businesses give us much less $ than they are supposed to. Upvote this so that the delevoper can see it.
 "Business"){kind=icon}
It shows how much income you earn per one tick of this business. (You can see plus before amount)