In that range, I have a Scrapyard Dogfather, that laughs at everything I throw at it. I also have a range of $6 Tramontina machetes that have more than earned their keep; 14" bolo in particular.
If you can score an CG FBM, then that should settle it. This would require monitoring the Busse F/S forum. With Busse's warranty, I doubt 'used' would make much difference for a user.
Otherwise, a Ranger RD-9 will do you right, as will a Scrapyard Dogfather.
Fehrman's and Swamp Rats won't have any trouble getting the job done, either.
Maybe some of the larger Bark Rivers, or Fallkniven.
If you don't mind the shape of a Kukri, Himalayan Imports will set you up with a real workhorse chopper, for quite a bit less than your limit. Check out their subfuroms here, especially the DotD (deal of the day) thread.
Considering your budget, and assuming you aren't in a rush:
You may also consider a custom or hand-made knife, by one of bladeforums resident knife-makers here.
So far, I've only had the pleasure of dealing with Dan Koster, whose excellent Bushcraft knife I use; I have full faith his larger models are just as well-made, and his website is good fun to peruse possible orders. Gossman and Fiddleback have some designs that have been catching my eye, but there are also plenty of other knife-makers here who have a good reputation. Siegle being one, as Kimo alreayd mentioned.
Look around and see if any other makers have the style you like.
Either way, if your budget allows the addition of an inexpensive machete, as well as the large fixed blade, then I would suggest you include it. Aside from not minding if you abuse or lose it, dull the edge, take a hacksaw to it and change the profile, or try a different edge angle, there are times preferential to beating on a cheap piece of steel now and then for the dirtier jobs. Tramontina, Martindale, and Linders are very usable; listed from thinnest to thickest stock.
Take a look at the scrapyard dogfather, Ranger knives or swamprat.
