Call around, some guys have half day rates, I know one here and he will do those small jobs on the side. Still not cheap, but it gets the job done...As the fellas have already said though, if you can come up with a day's worth of work, more bang for your buck because when a good operator gets going, they can get a lot done.
Local area Landowners would be a good source, also the county AG office, maybe even the local hardware, or feed store can get you a few names to call. Also try calling the closest cement place, get names and burn up the phone.
From my experience, the size of the dozer often dictates the daily rate..
Friends don't let Friends drink and post.......
The first 5 day's after the weekend, are the hardest....