When you are trying to buy something that is not listed for sale, it is reasonable to expect to pay some premium over the value of the item. We see this all the time when companies are taken over. These deals also do not necessarily close in a mater of days. When Dell went private recently, it took over a year for the deal to be completed.
Even though Bro is the one being sued, there is a presumption of innocence in our legal system. This is at least some of the reason why he is being given his choice of dates of when to meet. It is also unreasonable to expect him to be cooperative in this matter, because he has the same stakes that you do: if you lose this house, you are unlikely to be able to afford to buy another house unless you pick one of the “ten cheapest places to live” real estate markets. He is not a “motivated seller”, so other motivations have to be found. I don’t know whether there is the possibility of the judge being called in immediately should Bro blow off the next meeting, or whether more time has to be allowed to try to come to an agreement before the case reaches court.
What are the consequences of the administrative dismissal of the case? Usually when a case is dismissed, it can be refiled. Was the instruction to you to have some sort of arbitration or negotiation with Bro and his lawyer before the court would hear your case? Right now, you are in a position where you have to try to get Bro to agree to a buyout price, presuming that the “hammer” of going to court and seeking a partition of the property still exists. Another question that I’d ask is whether homes of your type and condition are selling above or below the appraised value. This would affect the price that you would offer him.
Though you don’t want to bring all the drama with you and Bro up to your lawyer, it would be worthwhile to mention that this isn’t the first time that he has failed to pay his part of the costs, and you have enough data to make a case for being “slow pay/no pay” to be his standard operating procedure. If memory serves, you had a tax lien on your house a couple of years ago, so he put ownership of your house at risk through his actions and wound up costing you more money, because you had to pay interest to the holder of the tax lien.
One thing to check is whether the form of ownership of your house is “joint tenants with right of survivorship”. If it is, that’s good, because should Bro die, you inherit his interest in the house, even if his will leaves it to someone else.