I recently built a new house. I had to clear about 2 acres of fir trees, which comes out to be about 400 trees. I wanted to have the stumps ground up in one of those big grinding machines. It just seemed to be more eco-groovy than burning, and we wouldn't have to deal with getting a burn permit in the middle of a forest. Then I found out the price.
Three outfits bid the job. The most common price was $5000.00 to setup (yep, thats a five thousand), plus $1500 a day to grind. That doesn't include the trackhoe required to load the stumps into the hopper, which is $1000.00 a day. In theory, it would have taken 2 days, making this a $10,000.00 bill.
The burn pile cost me $50 for the permit, $100 in labor to have someone sit and watch the fire burn at night, and $10 in beer to keep my labor happy overnight. The trackhoe was onsite doing the clearing anyway, so that still cost me a few grand which was paid for by selling the timber.
Great idea, overpriced in my area!
Kevin