What is the ruling on holding an extravagant honoring ceremony that includes praise and the slaughter of camels, and is there any sin incurred by one who refuses to participate in funding it?

Spending large amounts of money on such occasions is inappropriate, especially given the presence of needy people in the Ummah. You did well by refraining from participating. You cannot be forced to pay your money, for what is taken by shyness is not permissible; as the people of knowledge say: "What is taken by shyness is like what is taken by force," and due to the hadith: "The wealth of a Muslim is not lawful except with his willing consent." Furthermore, obligating these matters and compelling people to perform them is not permissible, because it is an imposition of what Allah and His Messenger did not obligate, and a taking of a Muslim's wealth without his willing consent.