They showed up yesterday and mowed, edged and trimmed the lawn and tilled the garden. This afternoon, when I switched on the sprinkler was when I realized the drawbacks of a $75 job. One of the sprinkler heads was broken -- it must have been sticking out and the fellows must have mowed the head right off.
A trip to the hardware store, and I came back with a 4" pop-up sprinkler. "Screw the old one off," the sales guy told me, "and screw this one on." Easier said than done. I wrenched the old one loose but the hole that housed the sprinkler flooded immediately. So, the old sprinkler is off but the new one's not on. I'm hoping that the place drains enough by tomorrow for me to clean out the threads and screw this on.
UPDATE: Nope, the sprinkler pipe is below the water table. I need to call a sprinkler repair guy to pump out the water and replace the pipe. Another $100 perhaps.