Insurance rates on office buildings - broker recommendations

Hello BP Folks,

I have only invested in residential real estate (MF and SF). I'm looking at knocking down my first "commercial property". It's a small single story office building. Roughly 6000sqft (4 - 1500sqft) offices located in Mesa, Arizona. Current agent is putting a replacement value of 765,000 with a $3600/yr premium. I have a couple questions.

• What does everyone use as a budgetary figure/formula for insurance premiums?
• Can anyone recommend a good commercial agent/broker?

Thanks,

Casey