Hi Nicolas, it will depend on your specific home. Appraisers will look at similar units to yours that have sold so unfortunately an average price per square foot won't give you a realistic value. For example smaller two bedrooms tend to trade at higher price per square foot values, as do units with NYC views.. similarly units on 3 to 4th floor walk ups trade at a lower per square foot value.
If you'd like a broker price opinion report I can help you with that to give you a better idea of what your condo will appraise for.
Hope this helps!