For getting brush and trees gone, forestry mulching is usually the cheapest full-clearing method — one machine, one pass, no burn piles, no haul-off, starting around $350-$600/acre on light growth. If the ground is open and you only need it maintained, brush hogging is cheaper still ($100-$250/acre) but nothing is removed — it regrows. Beware 'cheap' dozer quotes that skip debris handling; burn piles and haul-off get added back later.