Is it Islamically permissible to take the legal expenses and surplus resulting from a court judgment to recover the sum of $8,000, after the sale of a plot of land, for which this amount was paid, became impossible?

A promise to purchase is legally and religiously binding if the promisee incurs costs as a result of it. If the buyer has no valid excuse for not proceeding with the sale, and the seller or intermediary has incurred costs because of the buyer, then the buyer is obligated to complete the sale or pay compensation for the damage. However, if no costs were incurred, the seller has no right over the buyer merely due to the promise, and must return what was taken. If the seller refuses, and the judge rules in favor of the buyer, including additional litigation fees, the buyer is entitled to take all of that.