SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

A few people in my subdivision have just has sprinkler systems put in. The company that does the installation does not to the plumbing in the house, but they do recommend somebody. I checked out a house that the recommended company did and I checked out a house that the home owner did it himself (atleast as far as everybody else knows ). Anyway, the recommended company put in a watts 007 dca, whereas the guy that did it himself put in a watts dual check valve. I should state that we don't have any city codes to abide by (we are all on our own wells), so I am wondering which one I should go with and why? I am thinking I go with the dca since that is what this recommended company always uses for sprinkler systems, but I want to be sure. Also, how do I tell which size I need 3/4", 1"...(I am not doing this myself, I am having a plumber friend do it, but he hasn't been over yet to check it out). One last thing, what would be a good price for the installation? I can get a 1" dca for around $90 shipped, so just for install, what should I expect to pay. The recommended company is getting 500 total. thought that was high considering the dca only runs about $100. Thanks for all of the info.

Ray - Thanks for the reply. I guess I thought 500 seemed a little high if the valve only runs around 100. My pressure tank is right next to the exterior wall, so there wouldn't be much to run up and out.
The company is installing 41 heads in 10 zones. They use all Hunter (PGP heads, 300i controller, not sure on the valves). They use Poly pipe (we are in northern IL). They were about 1700 cheaper than the local people that do it around here. This company is charging 3300 for everything installed minus the plumbing to it which is where my questions were coming in. There is a licensed plumber that lives down the road from me that already agreed to put the valve in for me, but I wasn't sure what to pay him.