I think it's very important to have some grass in the garden - people like to have a green vista. When househunting, "low maintenance garden" always sounded alarm bells for me - made me think "oh no, it's all concreted over, it'll cost a fortune to dig that up." I think option 2, where you pave some and retain some grass, social space, etc is better for conserving value - and if you can get nice paving and some shrubs or trees into the dogs' half, it can still feel like "real garden".