Your property sounds similar to my family’s (see post #142 above). We all lived in what looked like an old mansion that was converted later into a full house, a duplex, and a connecting door. But it had multiple bathrooms because it had multiple apartments.
I’m not sure whether fewer bathrooms cuts down much on the price of a home. But, if it does, well, I knew large families who shared one bathroom. The only problem arises when the family comes down with the flu or a virus. I raised my kids in a home with one and a half baths, and we rarely used the half bath. Now, I live in a place with two full baths, so I’m spoiled rotten now. lol
Only one bath needs to be finished at the time of initial purchase in theory.