Metal roof in Bay Area?

We are trying to find a metal roof contractor in Bay Area. We've got 2 bids so far, but the prices are pretty high.

We thought that the metal roof should be relatively cheap and data from construction sources indicate a $600.00 per square for national commercial standard with a $200 increase for this geographical area.

Anyone has experience with this or can recommend a good & reasonably priced metal roofer in this area?

Keep in mind that metal roofs create a partial faraday cage, keeping cell phone signals weak in your home.  My parents just put one of these on their house and now get terrible phone reception in doors.