Best Under-Ground Sprinkler System?

I am looking at potentially getting the Irrigreen Smart Sprinkler system but wanted other opinions before pulling the trigger.

I have a ~5,000 SQFT Bermuda lawn in GA along with flowers/plants along the side of the lawn. I like the idea of Irrigreen because I can not only water the lawn but also program it to water the flowerbeds etc. My lawn isn't a perfect square so I like that I can program it to go along the curves and not waste water on the walkway/driveway. Also, I plan on installing it myself unless I can find a reasonably price to contract the installation so having less trenches to dig is a plus with Irrigreen.

However, it is quite expensive of a system and I would prefer to spend less money. I would also probably need a plumber to come out to complete the entire install (not sure if this is requirement for all systems.)

Any recommendations on an easy DIY underground sprinkler system?