Just noted that pulse flow meters are going down to affordable prices. 2-wire Hunter HC-075-FLOW 3/4″ FNPT Flow Meter at $88 from Sprinkler Warehouse. 1-inch size is about $20 more.
RainBird has finally got into the niche market with their own FMD Series Landscape Water Meters. Haven’t seen the price but it’s probably not the cheapest one.
As I noted before, it’s hard to beat the price of EKM Metering’s stainless steel ($70) 3/4in. pulse output meters. They were one of the first to offer these kinds at a low price and they are California-certified for potable systems. Wire it up to a pulse transmitter w/gateway device and you can get high-flow and low-flow detection with SMS alarms independent of controller itself.
Search for pulse water meter suppliers. Some are cheaper (https://www.flows.com at $69) but that’s with no pulse output.