I have a lawn tractor that I use to cut my yard and my grandmother's, across the street. Of my 4 1/4 acres, I'd say that maybe 1-1.5 acres actually gets mowed. The rest is either forest, driveway, structure, etc. My grandmother's yard is about 1 1/4 acres, but once you account for the house, driveway, garage, fenced in area for the dog, etc, it's probably down to under an acre.
To do it all probably takes about 2 1/2 hours. My Granddad bought the tractor back in early 1990; probably paid about $1300-1400 for it. Considering it's going into its 18th season, I'd say we got our money's worth out of it! It needs a new battery from time to time and an occasional belt, and some suspension work here and there.
I can actually get most of the grounds with the tractor, so I don't use the push mower that often. There are some spots I can't get, such as the dog run area at my grandma's, or a courtyard area at my house, and I'll usually hit them about one a month. I try to hit the parts of the grounds with the tractor every two weeks, although sometimes I get lazy and put it off. And sometimes the grass grows fast enough that even two weeks is too long.
I have no idea how much a lawn service would cost. I think my neighbor pays about $50 per visit. But they do everything...tractor cutting, push mower cutting, edging, trimming, etc. She complains about the cost, but I think it's a pretty good deal. Heck, I wouldn't do all that for 50 bucks! I told her I'd cut her back yard area, which I can hit with the tractor in about 20-25 minutes and not charge her anything, but then that would leave her with all the other trimming and such.
I think I was 9 when my Granddad started letting me drive the tractor. Back then, we lived down in Southern MD, about 40 miles from my grandparents, and every other week during mowing season, he'd load that tractor up on the back of his truck and bring it down to cut our grass. I remember how exciting it was as a kid, getting to drive that tractor. The novelty wore off fairly quickly, though. Seems like when it's something new and different, it's fun, but once you realize it's just another chore, it loses its charm.