How to determine value of a commercial property w/ no list price?

[Patrick Philip]

I have found several commercial property websites. Many of the properties have no list price. They are relying on me to make the first offer. How do I determine how much I can offer?

I can assume that I should estimate how much rent I should receive, but how do I know that? Are there companies that perform this kind of analysis? From my job as a property manager, I know that maintenance costs can be highly unpredictable. Aside from that, other costs like debt and property tax should be easy to estimate.

Should I take future expected rents into consideration? How would I know this?