A father conveyed his property to his son and daughter "as joint tenants with right of surviviorship, but if they ever attempt to sell the property during their lifetimes, a right of first refusal based on the sale price is hereby granted to my sister." Unbeknownst to the son or the sister, the daughter quitclaimed her interest in the property to a purchaser. The following month, the daughter was killed in a snowmobile accident. The purchaser of the daughter's interest filed a suit for partition of the property. The son filed an appropriate counterclaim for quiet title, asserting that he was the owner of the entire parcel. The sister also filed a counterclaim, asserting that her right of first refusal was valid and that she was prepared to exercise her right to purchase the property for the contract price.
In a jurisdiction in which the RAP is unmodified by statute, how should the court rule?