Something that was unheard of a relatively short time ago is now becoming more commonplace. Once the legal formalities are completed, it can be helpful and indeed fun to mark the separation in a ceremonial manner.
Maybe the two of you would simply like to honour the time you have spent together before moving on? Perhaps a bigger occasion attended by family and friends would provide a more suitable conclusion to the end of the relationship?
Serious. Emotional. Humorous. Anything really. This out of all the ceremonies is one that starts with an entirely blank canvas and can involve as little or as much as you want.
Since the scale and duration of these ceremonies are extremely variable, a price can be negotiated after the initial discussion.