I believe all recent sales have shown the team sold more than for the value assigned by someone outside the deal.
Plus, you have to add value for prestige and an increase in value because someone just wants to be part of the league.
The players vying for this type of prize aren't scared off by a few hundred million. And, if you want in, you also have to look at the next chance of getting in. If that is slim, up goes the bid.
Finally, it doesn't matter what they are perceived to be worth now. A sale is well down the road.