Here is a sure-fire fair way to resolve dissolving partnership issues:

Step 1: Flip a Coin and determine a “winner” of the coin flip. (any game of chance will do).

Step 2:
The person who loses the coin flip must choose a price for the house.

Step 1:
The person who wins the coin flip decides if they wish to buy or sell at the price set by the person who lost the coin flip.