Advise young adult child to buy house or not, with current tax situation?

Prices continuing to rise rapidly is not a promise of future returns. If anything it is a warning of a future correction. The northeast also includes a wide variety of real estate market that have a wide variety of different trends. For example, Hartford Connecticut is in the northeast, yet shows a very different trend from what you described. The median sales price in Hardford was $165k at the start of 2007, reached a min of $93k in 2015, and is currently ~$120k. The metro closest to the area I grew up in upstate NY shows a different trend from both your description and Hartford. It had a median price of ~$165k in 2007, it reached a min of only $155k (2013), and is currently at ~$180k There was little fluctuation, but the increase was slower than inflation, so it would still likely be an investment loss.