You can actually get screwed more by going from X to 4X than by going from X to 2X _if_ you want to buy your new house in the same market. In the simplest case

You can actually get screwed more by going from X to 4X than by going from X to 2X _if_ you want to buy your new house in the same market. In the simplest case, consider that you want to move to a house of the same value (e.g. closer to work). That's a lot easier to do if there was no taxable appreciation in value than if there was. But even when downsizing you could run into problems; see the example I give elsewhere in this thread: https://news.ycombinator.com/item?id=15706565 https://news.ycombinator.com/item?id=15706565