You sure like to bang on the same (non)issues...
Your idea is based on this vague premise that
every season a top team adds 1M to their value
. My idea is that this just not true. First, let me make sure that you are not suggesting that a new team in a div IV should be able to compete with teams in the top division right away? Not that loony, right? Good. The way I see it is that the economic is not built in a way that teams can just stockpile lots of money (except for countries with very few teams, not going into that). Basically, there is a given amount of talent you need to compete with the other teams in your division, and that correlates to a given salary range. Teams that overspend on salaries get into financial trouble, you can't go below -500k. So if a team wants to win, then any money lying around is spent to improve the roster, in order to win. Standing around with crappy teams just to make money is not really the point of the game.
Teams that promote get cash bonuses to help them bridge the gap to the higher division teams. And the arena size debate is also nonsensical, since bigger arenas then have to lower prices to fill the seats. So having 8000 bleachers @ $15 each is the same as having 12000 @ $10 each.
Point is, it takes time and patience to build a good team and take it to the upper divisions. You only needed one season to promote to div IV, so it wasn't so hard for the newcomer... A "salary cap" here is already in place. Teams have limited sources of revenue, so they just cannot afford to overspend on salaries, they would go bankrupt in a matter of weeks.