Is it grass, rock, asphalt, concrete, dirt? Is it a huge pile, flat, convex, lumpy? Is the 4" how much soil you adding, extracting, moving?
Vague posts get vague answers...
At my house grading a 14x14 section costs a 30 pack of cold beer, a good friend, and two rakes...
I had friends in CT with great properties. I did not know they were getting by so cheap. Neither owned rakes though. What kind of beer? Cans or bottles?
I would add to the list of variables you did not include?
This plot on some sort of slope that requires rock climbing gear? I am actually guessing it is relatively flat but you talk of adding 4" which seldom works out that way if it is unretained soil?
Why does it need regrading and does it need something to retain the regrade first? Upslope or downslope? Because regrading something, even for beer, will scare off friends even owning their own rakes if it happens after every rainstorm or even every season?