Money and a Professional with talent can make anything happen. But, talk to a realtor as to how losing a bedroom would negatively affect your resale. It ain't a cheap project, and you might spend the 150K for the addition for more space that would add some value, rather than a 100K rearrangement of space that would be guaranteed to lose value over what you paid.

IMO 3 bedrooms with one of them a master main floor suite is a selling feature where I live not a bad ROI As for what you want to do this will need a good designer and $$$$$

your home would become more attractive to some buyers (empty nesters, those with older children, young couples with no children who arent thinking ahead), less to others (couples with babies/young children who don't want to be downstairs from them). this is somewhat what drives the price.

without showing a floorplan, not sure if one of the bedrooms downstairs is large enough to be the master with the other bedroom divided up to expanded bath/closet/dressing room. you could fool some buyers with a bad floorplan but not all of them.

a young couple that is friends of my daughter just bought a cape in the greater boston area; both are professionals, it has one bathroom that is downstairs, all of the bedrooms are upstairs, and they spent a ton of money for it. but they had lost every other house in bidding wars. crazy days.

Appreciate all the comments. I am a realtor and considered the ROI before purchasing. I live in an old established neighborhood circa 1950, where many homes have converted garages for square footage. And it's not unusual to find a 3 bedroom home. I believe that a master with private bath and decent closet will pay off in the long run. As we all know, you can please everyone. No to find someone to help with the design. Do I consult with an architect or interior designer?