Depends on where you hunt, all US federal wild life area prohibit any wheeled vehicles, this means even bicycles.
Where motorized vehicle is allowed, ATV should perform much better, and possibly cheaper too simply because there are much more demand of 4 wheeled ATV rather than 2 wheeled motorcycles.
All terrain hunting bike: $2199 http://smartbikeparts.com/search ... vfbROBYQaAt758P8HAQ