pay the selling costs, be happy that their is no tax in the gains and avoid arguing over details like this the rest of their lives which likely will happen if you keep the properties.

If you are keeping the properties, imho, the value at the moment is appraised value less selling costs because eventually they will likely be sold and there will be selling costs.

You did not make or clear why the size of the pot matters, but, if some want to buy out others, I would net out the selling costs.