It's literally crazy. We bought our house last May and have seen a 45% increase in value (according to online estimators which are usually off by a bit). So far we've lucked out. Our house was built in 1920 and had major work done in 1950, 2005, and again in 2009. Over the past 9 months the only major issue we've had is updating our furnace and heating from oil to natural gas (which ends up saving us money in the long run). I do wonder about many of these flipped houses though. Just one street over I've seen 3 1920's houses flipped in a few weeks and sold for crazy high amounts. These flips have to be mostly cosmetic. They make the interiors look amazing, but the house itself is still shot.