Is $900 for 1500 sq. ft duplex a good price?

We are moving. It will be 3 bedrooms, and a full basement. Do you think 1500 sq ft is big enough for 3 adults, 1 child? It's in a really great location, which is why we want to move there. I don't ask other people how much they pay for their house, but who cares...How much do you pay a month and how big is your place? What do you think?