Let's imagine that each member of our crew loves Cheese Whiz. It is loved so much that we cannot imagine doing the trip without it. What happens, while we are out sailing, when we run out? We buy more, right? Sure, but doing so will be far more expensive than when in the USA. As a product of the USA, Cheese Whiz anywhere outside of the USA will be more expensive than in the USA. It costs money to transport it. So, there we are, on our boat completely void of Cheese Whiz in Tonga. What do we do? If it is available locally, it will be more expensive than if we bought it back in the USA. We could attempt to have someone ship us a box of Cheese Whiz. That would be extremely expensive too, and maybe illegal. The solution? Make full immersion in local cultures part of the experience. If drinking Cow Whiz is what they do, you can bet it is cheap and probably okay for you so you might as well start drinking.
Somehow many people around the world survive just fine on yearly salaries of a few thousand dollars. If that is the case, then the price of food and necessary goods must fit within their budgets (government subsidies are not available in every country). Consequently, consuming the goods with the locals is the best way to keep costs within our budget. Carrying our culture with us would make this entire exercise much more expensive and would require us to delay the trip. Time to start drinking Cow Whiz!