Reasonable dollars per squarefoot for a house?

My wife and I visited late last year, both loved it and signed contracts for when we finish residency this summer. We're now looking at houses to buy and were wondering what seems like a reasonable $/sqf for a house? Seems like +/- $400 is about average? And myself coming from MA I was quite surprised that more than 3/4 of the listings were houses that are in an HOA?