Licensed Irrigator
I've read some valid comments on estimating the price per job and they are all good. The other side(s) of the coin are this: 1)Consumer mythology and 2)Outlaws.
1. Consumer mythology. Consumers still quote to me $250-300 per zone as the price they heard their neighbor got. Usually their neighbor had an install done by an outlaw, you have to educate them on the cost and why things cost what they do to sell them.
2. Outlaws, aka Unlicensed. Some of them have actually worked for a licensed irrigator. Others are lawn care operators (mostly illegal aliens in this area) who offer to do it for their cheapskate homeowner. You have to be licensed to set a tap and backflow in this state and about 50% of the systems I get called to work on are done improperly (some have no backflow at all).
Customers quote the $250-300 per zone figure and then tell me they want 3 zones. I use the analogy of a car. I explain that a car might cost $30,000 and therefore we could say it costs $7,500 per tire. We cannot go in and say "I want a car with only one tire". I then show pictures and examples of the type of systems they can get for $250-300 per zone, pictures of disastrous plumbing, not enough water and of course mention that the state of Texas will fine them if it is installed by an unlicensed individual.
Some homes have good water pressure and a 1" meter, this means I can put up to 30 gallons per zone if I need to. This is helpful on a large property but does not allow for hydro-zones, i.e. the back yard may be full sun and the side has no sun and poor drainage. I don't need the same application of water on both zones, need to hydro-zone. A small residential yard has 5 hydro-zones usually and 1 of them is drip irrigation for the flower beds and landscape along the house.
The ones who understand and want to pay me my price (I usually price by the head, $75 per rotor and $50 per spray minimum cost on a normal install with normal soil, $100 per rotor and $70 per spray on hard clay or steep terrain or difficult install).
Make sure you call your local utility before putting a shovel in the ground and then invest in your own test equipment. On my first job I hand dug over the gas and underground utilities as I am supposed to and then started my trenching machine 3' away from the mark put down by the gas company. 3 feet after this I hit the gas line!!!
I took digital pictures to show that I was clearly well away from their mark, the gas company re-marked and found that the line was marked up to 20' off in places!!! Now I check my own as well as require them to mark all their utilities.
Hope this helps.