If Cost is your main concern and you also have to consider the fact that you want to keep your acreage organic. Then maybe your best bet would be to rig your farmstead into fire lanes with the moldboard plow or Dozer, cut enough dirt to ensure that the next step (controlled burn) will not get out of hand, checker board the acreage and do smaller sections of say two to three acres at a time. Get your burning permit! As the scrub gets torched, it will naturally leave your land slightly fertilized and ready for pasture. Next year you will be able to start pasturing the land and the increased cattle presssure on the left over scrub should hinder the natural regrowth of the trees and brush. No chemicals, only fertilizer! then you can bulldoze, mulch,rip, tear, smash, dig, pile, or whatever you need to do in order to finalize your MGT. Plan. I will say this though, controlled burns will save you a ton of money and make your decision a whole lot easier on wether or not to buy that piece of equipment. In addition, your land will not be subjected to the three year scrutiny that is our certification process to be certified organic.
A good person to contact for the info on controled burns and it's impact on the field conditions would be Gary Zimmer, (Midwestern Bio-Ag) Blue Mounds Wisc. Sorry I do not have the Phone number right off hand, but if you email me I will gladly put you in touch with the local Midwestern Bio-Ag Agronomist.
just one farmer to another
Don't get me wrong I still like my yellow iron as well, it's good for the nerves! cuzz farmin shot them to ****!!!