The experience, knowledge, and fun that I'll gain will be invaluable! However, to clear a 2 acre portion of 4in-12in hardwood/pines, are you really saving any money in comparison to hiring a guy who will not only correctly clear the area, but do the rough grade, septic, foundation excavation??
Short answer: Yes. You will save money by taking working hours out of the job. "Dirt" contractors (for lack of a better term

) base their fees on how long a job will take along with what materials are going into the job. Anything you do that shortens the job time saves fees as long as what you do isn't creating a mess. :laughing:
Some things you need to decide, and maybe the first thing a contractor will ask you:
1) What will you do with the trees? Firewood. Chip the small stuff on site. Burn. Sell some decent logs. Whatever.
2) What will you do with the stumps? Pick an accessible site on your property for stump dump maybe?
3) Are you leaving any shade trees? The more you leave and the closer together they are, the longer it takes to work around them and some may die anyways from root compaction and exposure.
If you make piles of stumps that the contractor can load into a dump truck using an excavator, that will go fast and save you money. If you can get them loaded into your dump truck and haul them off, that will save even more.
4" - 12" mixed soft and hardwood stumps should not be a big challenge for a bulldozer. You could probably push the larger trees over first then cut the tree off the stump with the chainsaw before you get the trunk all dirty. Dirty logs are saw chain killers, you will be forever sharpening the saw chain.
If tree work is new to you, then start with small stuff and get some practice. Wear ear & eye protection and chaps when cutting and a hardhat all day. Pushing over trees with machines can be very dangerous. There are dead limbs that can fall on you. Trees under stress don't always do what you expect, they can split, shatter and twist in odd ways, pull other trees down, etc. A 12" tree trunk can be made to act like a very powerful and deadly spring if you get one or both ends of it trapped and start pushing on it. If things aren't going smooth and easy you are probably doing something you shouldn't be.
Grading difficulty depends on the site. Mostly you want to manage water run-off directing it away from the house and driveway. Now is the time to plan ahead for any future buildings on the two acre clearing so the basic dirt prep is done for those at the same time.