There is no definitive answer to this question as the most expensive hunt in the world depends on a number of factors, including the location, type of game being hunted and the specific needs of the hunter. However, some estimates put the cost of an African safari - which is often considered to be the most expensive type of hunt - at around $100,000 USD. This figure takes into account airfare, accommodation, equipment and other associated costs.
Of course, not all hunts are created equal and there are many that cost significantly less than an African safari. For example, deer hunting in North America can cost anywhere from a few hundred dollars to several thousand dollars depending on factors such as where you hunt and what type of deer you're after. In contrast, big game hunting in Alaska can easily run into tens of thousands of dollars due to the remote locations involved and the need for specialized equipment like aircrafts or snowmobiles.
Ultimately, it's impossible to say definitively which hunt is the most expensive in the world as there are simply too many variables at play. However, if money is no object then an African safari is likely to be one of (if not THE) most costly experiences you can have when it comes to hunting.