Get two other quotes to get the feel.

ditto.
there are too many variables to consider when doing an irrigation cost estimate.
a contractor has to visually see the site and run a few basic tests to understand what he is up against in order to provide you with an apples to apples estimate.

Again, try to get several quotes to establish what's high, low, and in between. Depending on the configuration of your yard, where and how the lines can be run, the connection to the water source, any rain sensors, etc.... it's highly site- and project-specific. If you know what brand you're using, manufacturers typically have a list of local representatives or dealers who are experienced with their specific product. That could add some weight behind any figure they come up with, but it's always good to have at least one or two others for comparison.

- Audric

Thanks--I'll see if I can provide info that's helpful, and I'm learning a lot from these responses. I understand that everything is site specific, and I will be getting multiple bids, but I'm trying to get a sense of the parameters of what a reasonable bid is. No brand names have been mentioned or recommended.

The lot is flat; there are actually two mains that they can draw from so piping to the main(s) won't be as long as it might otherwise be. There will be 2 rain sensors. 7-8 of the zones will be for planting beds, the remaining for lawn.

Would anybody at least like to weigh in on what would be a reasonable high, medium, low, even without knowing more than this? Perhaps simply based on own experience?