Anyway to estimate insurance without reaching out to my broker for every property?

[Kadeem Kamal]

I'm currently planning to purchase a commercial multifamily building in Chicago with the proceeds of a 1031 exchange. I am looking in the 750k-1.1m range with between 6-10 units. I haven't sold yet, I've been analyzing property to get a head start on the 45-day timeline of identifying the potential replacement property (and because I enjoy analyzing property). 

One issue that I'm noticing is the range of reported insurance costs. I've seen some as low as 6k and as much as 14k annually. I know that ideally, I reach out to my broker or any other reputable insurance provider to get a more accurate estimate. Given that I'm not positioned to buy just yet, and simply running the numbers, is there a rule of thumb for estimating insurance costs that would make sense in Cook County?