BK9 is a great chopper, but with only a 9" blade and 0.18" blade stock it's not the heaviest or longest blade out there in your budget.
Ontario makes some great blades, their SP series has some great deals for under $100 with some long and heavy chopping blades.
Condor is even more focused on chopping-size blades, some of their offerings like the Discord are great deals for the amount of knife you get (Micarta scales & leather sheath for under $100 is pretty sweet).
My personal favorite for budget choppers is the Ka-Bar Parangatang, same steel as the BK9 but 5" more blade to play with and a chopping geometry as well. For under $100 it's the best deal in my opinion. One caveat is the handle isn't for everyone and might not be comfortable for some.