How big is the overall space 2,000 sq. ft. or 20,000? That will affect the price. Also there is a big difference between office, retail showroom, and warehouse space. If the building was built in 1999 I would imagine it is in pretty good condition, doesn't require anything more than a phase one EPA, and should be fairly efficient. However those are just guesses. Other factors include but are not limited to: Lot size, build out, tenant finish, location, current tenants (if any), zoning, and frontage.
There are so many factors to a correct valuation, I would need much more info to give a better answer.