Buying on the short term in a down market may not build you equity and may net you a loss. However, buying on the long term, enough to ride the market back into an upswing, you fare better at building equity over time. If you already own a home too, and need to upsize into something bigger, buying up in a down market may also be a move to consider. As the market turns back, so does your equity postiion.
Of course there would be mortgage factors to consider as well. Possibly discussing your needs with a financial advisor may help you determine if now is the best time for you. I service Orange and Rockland counties, if you would like a more specific evaluation of your area, I would be happy to be of service.