How do you put a price tag on a vacant retail property

[Diane G.]

I see potential in this property IF I can find a tenant, which can be YEARS away....How do you put a price tag on it now?  Is it worth of risk? It is categorized as retail, I think it is really more of an office type of commercial.....

http://www.loopnet.com/Listing/20140012/851-Van-Ness-Ave-San-Francisco-CA/