I looked at getting my strip levelled a couple of years ago and was quoted 3.5k just to do 300m of it.
The company that quoted for the work guaranteed a level surface and when I looked at the kit they were using (everything lazer guided and two hundred and fifty grand to buy it) I could see why the job would cost so much.
Decided against it in the end (not enough pennies in the kitty) but if I came into a windfall I'd get them on the phone tomorrow.