It all Depends upon the willing land lord and willing Tenant.
it is a free market economy.
The range can be NNN 12- 20/SQ.FT.
The office Buildings are of different catagories so price per square foot will vary accordingly.
You can reach me By e-mail: firstname.lastname@example.org
I can find some office space off route 17 in Bergen county where you can rent from 1000 sq.ft to 5000 sq.ft at NNN $15.00/sq.ft.