Hi. Welcome to JA.
That is a question that is difficult to answer without seeing the property. There are many things t6hat would need to be considered by the person doing the work.
Is the soil hard to dig?
Is there any ground water to be concerned about.
How much soil will have to be moved.
Will soil need to be added, or hauled off from the property. If so how much.
Is there any debris on the property that will have to be disposed of.
Will a gradeing permit be required.
Is there access to the property for heavy equipment.
Can a small piece of equipment (like a Kubota tractor) handle the work, or will some serious power be required (like a D-8 Catapillar).
Will the property need to be sloped for proper drainage.
Will swails be required.
Will a drainage sump be required.
Is soil compaction a concern.
Are there any underground services that will need to be USA'd.
Does the property boarder a county, or city maintained road.
As you can see there are many concerns that the potential contractor or soils service must take into considration before they can give you an acurate bid.
As an example of what I have to pay for a good operator to do some tractor work:
The contractor that does most of my dirt work gets $125.00 per hour to bring in his Case 750 with a gannon bucket on the back.
He can scrape off, and grade a 2100 sq. ft. house pad, at a 3 - 5% slope, on a piece of property in the Golden Hills area of my town in a few hours. The soil in the summer time is like concrete if you try to digging anything by hand so he earns his money every time.
Please advise if you require further information.