I do a little spraying around the barnyard with an ATV sprayer but we hire a guy do hit the actual fields.
He doesn't mess around, big JD with 120' booms. Covers a chitload of acres in a day.
Just got done doing 1100 acres, $23k.
Makes a guy sick thinking about the cost but we simply do not have the time to get it done and when you have a bunch of weeds coming it is really nice to just make a phone call....
My dad does run a 50' SpraCoupe down on our smaller flood irrigated fields but that's only maybe 150-200 acres.