Incorrect example
Guides are by definition should be able to guide. If language is required to be a guide then the guide should learn it. i.e. French side should find a guide who speaks all the necessary languages and that's what actually happens in the real world. French side should find resources to make the communication happen, as I was suggesting I don't see why Papua New Guinea should pay French side for a guide as you were suggesting
Selling the goods is also incorrect example, because goods are targeting local population thus should be useful and convenient for locals