If your neighborhood is more suited for families that need 4 bedrooms, this would not be a good idea. Often that extra bedroom will make a lot more difference in better resale value. It also sounds like you would go to quite a bit of expense to make these changes that would not likely get you the return on investment that you are seeking.
Remember, remodel for you at this point in time if you plan to stay, but don't use too trendy of a finish. Think classic, functional and well finished. Pull the permits if you need too, I know many people are looking for those now in offers to purchase.
Good luck to you!