Question: how much does it cost to install your own sprinkler system?
Answer: Cost is about $50, and takes about 1 minute to install if you already have sprinklers hooked up to a tap. Otherwise you can spend about $100 on polypipe and fittings and make your own sprinkler system (should only take you 2 hours or so), then get the above tap timer and automate it. O.P.