This situation isn't about an accurate price. This is an example of how to abuse the process to increase someone's taxes without the intention of buying.
You can't submit bids in this system without the intention of buying, if you have the highest bid you're forced to buy.
If you can demonstrate that the purchase offer is made because of personal animus, or the buyer has no reasonable and specific plans for the property (i.e. the billionaire buying out a small town without a workable business plan), then the courts would overturn it.
Ultimately, billionaires have lots of ways to mess with someone they don't like. If we don't like that, we should circumscribe what billionaires can do with their power.