Most lumber mills won't take any lumber that has been 'rolled'. Asking someone to push the tree over before they take the timber usually renders the wood worthless. Depending on the job being done and the size of the sawmill saw, a blade can cost thousands of dollars. One heavy oak tree that has been rolled around by a dozer can ruin a blade. That is why nobody would push them over for you.
Someone mentioned selling your stumps. Unless they are black walnut, they have zero value. Again, that is why you don't have people lined up to take them for you. Almost every place around my area simply digs a giant hole and buries the stumps. Even then, you will get some sinkholes since it's almost impossible to get dirt packed tightly around all the roots. It's usually no big deal, but I wouldn't want sinkholes (even generally small) appearing in my front yard or under my septic tank.
I assume that you can rent an excavator in your area. Be ready for a delivery and pickup fee on top of the weekly or hourly fee. Also, are you experienced with an excavator? Sure, almost anybody can operate one. The difference is not only the quality of a job that can be done by the experienced operator, but the time it takes to do the job. I'd say that I am an "average" excavator operator, and I can get done in one long day as a totally inexperienced operator can in a week. And, I'm not talking about someone who hasn't been around tractors; just someone who has not run an excavator. A really good excavator operator can get done in a week what would take me a month to do.
I don't know you at all and I don't know your level of expertise on an excavator, so please don't take my comments as saying that you don't know how to operat an excavator. You very well could be the person who can do in a week what it would take me a month to do. I was only trying to prove a point that sometimes a really "expensive" excavator operator may be cheaper in the long run for doing the job. Besides that, a really good excavator operator will give his opinion on ideas if asked, which may help you some. That same really good operator will also simply keep his mouth shut if you don't want to hear about his thoughts and only do what you hired him to do.
When I first got to where I figured was competent on an excavator, I'd bid on jobs and then lease a friend's excavator to do those jobs. One older guy I was doing a job for got me good and I still remember his point. In retrospect, I should have paid him for teaching me a good lesson in business. At the end of the first day of work, we were leaning against the machine and I was blabbering on about how much I got done and how I figured he ought to do this, and that etc. When I finished talking, he calmly told me that it was his understanding was that he was hiring me to operate an excavator for him, not to tell him what my opinion was on how he should use his land. /forums/images/graemlins/blush.gif Obviously he was right.
I mention this little story for several different reasons. If you get bids for the job, you'll figure out many of what I'm talking about. Also, unless things have changed, I could likely stay busy billing out $65 for just my time operating the machine. That wouldn't include rent for the machine, fuel for the machine, permits to haul the machine, etc. As in most things, you can find jerks out there who will do a crappy job and charge you an arm and a leg for their pathetic work. They most likely won't be around in a few years. Having said that, it wouldn't surprise me at all to have a good company charge $125 to $150 per hour to do your work. Depending on how far their shop is from your place, they will most likely also charge you travel time to get the excavator to your place to start the job and then again to get the machine back to their shop when the job is finished. If it is muddy, many companies also charge a surcharge to clean their machine when they get it back to the shop.
One of my best buddies owns a huge company that does just this sort of work in addition to specializing in underground boring work, like going under existing buildings and highways etc. He makes an extremely good living in this line of work, but mistakes can be costly. Whatever you do, good luck! If you have any more specific questions, just let me know.
