In div 4, I don't think the extra income from the 3rd game (which is probably only 50k or so assuming you are the home team) is worth it to risk losing a whole seasons worth of income. Maybe in the higher divisions it might be worth it as arena income is more, but for a mere 50k, is it worth risking the outcome of the final. The other team might buy a really good player and you accidentally foul out one player or something, anything can happen.
You are better off maximising your chance to get to the next division rather than risk spending a whole season in the same division for 50k.